uses an OU in active directory to find raffle winners. prevents users from winning multiple times.

Get-Winner.ps1

# Required scripts  --  this just loats the AD snapin or calls it remotely from a DC
.'\\ps1\functions\Import-AD.ps1'


$env:winnerListUNC = '\\DomainName.local\filestore\winnerList.txt'
$env:userOUSearchBase = 'OU=TheUsers,DC=DomainName,DC=local'

function global:Get-Winner {
    param(
        $ExcludedUsers,
        $WinnerListPath,
        [switch]$DoNotSaveWinner,
        [switch]$VerboseReturn
    )
    # Normalize parameters
    If ($WinnerListPath){$env:winnerListUNC = $WinnerListPath}
    If (-not (Test-Path $env:winnerListUNC)){
        $null = (
            $ExcludedUsers |
            ForEach {Get-ADUser -Filter "Name -eq '$_'" -SearchBase $env:userOUSearchBase -ErrorAction Stop}
        )
        [array]$ExcludedUsers = $ExcludedUsers
    }
    Else {[array]$ExcludedUsers = Get-Content -Path $env:winnerListUNC -ErrorAction Ignore}

    # Get current non-winners
    $nonWinners = (
        Get-ADUser -Filter * -SearchBase $env:userOUSearchBase |
        select -ExpandProperty Name |
        Where {$ExcludedUsers -notcontains $_}
    )

    # Get new winner
    $newWinner = Get-Random -InputObject $nonWinners

    # Update winners list
    [array]$winnerList = $excludedUsers + $newWinner

    # Update winners file
    If (-not $DoNotSaveWinner){
        $null = (
            $winnerList |
            Out-File -FilePath $env:winnerListUNC
        )
    }

    # Return results
    If ($VerboseReturn){
        $returnObj = [ordered]@{
            'Winner' = $newWinner
            'NewLosers' = ($nonWinners | Where {$_ -ne $newWinner})
            'OldLosers' = $nonWinners
            'NewWinners' = $winnerList
            'OldWinners' = $ExcludedUsers
        }
        Return (New-Object -TypeName PSObject -Property $returnObj)
    }
    Else{
        Return $newWinner
    }
}


# this is the basic form creation code from the original example.
# It assumes that the windows forms assemblies are already loaded...

# Set reused colors
    $dBackColor = [System.Drawing.Color]::FromArgb(52,113,90)
    $dForeColor = [System.Drawing.Color]::FromArgb(242,242,242)
        # R,G,B in 255 integer format, min 0,0,0 max 255,255,255


# Create form & inheritables
    $formMinHeight = 450
    $formMinWidth = 500
    $dForm = New-Object System.Windows.Forms.Form
    $dForm.MinimumSize = New-Object System.Drawing.Size @($formMinWidth,$formMinHeight)
    $dForm.Size = New-Object System.Drawing.Size @(($formMinWidth + 100),$formMinHeight)
    $dForm.Text = "RAFFLE"
    $dForm.BackColor = $dBackColor
    $dForm.ForeColor = $dForeColor


# Config form font
    $fontName = 'Calibri'
    $fontSize = ($dForm.Height / 8)
    $fontStyle = [System.Drawing.FontStyle]::Bold
    $fontSizeType = [System.Drawing.GraphicsUnit]::Pixel
    $dFont = New-Object System.Drawing.Font($fontName,$fontSize,$fontStyle,$fontSizeType)
        # 'font name',[int]size,[System.Drawing.FontStyle]::Style,[System.Drawing.GraphicsUnit]::SizeType
        # Font styles are: Regular, Bold, Italic, Underline, Strikeout
        # Font size types are: Point,Pixel,Inch,Millimeter,Display,Document,World -- defaults to Point if left off


# Config label control
    $dLabel = New-Object System.Windows.Forms.Label
    $dLabel.Text = 'Initialized.'
    $dLabel.Font = $dFont
    #$dLabel.AutoSize = $True
    $dLabel.Height = $dLabel.Font.Height + 2
    $dLabel.Width = $dForm.Width
    $dLabel.TextAlign = [System.Drawing.ContentAlignment]::MiddleCenter
    $dLabelStartLeft = 0
    $dLabelStartTop = ($dForm.Height / 2) - ($dLabel.Height / 2)
    $dLabel.Location = New-Object System.Drawing.Point @($dLabelStartLeft,$dLabelStartTop)
    $dForm.Controls.Add($dLabel)

    $dLabelWinner = New-Object System.Windows.Forms.Label
    $dLabelWinner.Text = ''
    $dLabelWinner.Font = $dFont
    #$dLabelWinner.AutoSize = $True
    $dLabelWinner.Height = $dLabelWinner.Font.Height + 2
    $dLabelWinner.Width = $dForm.Width
    $dLabelWinner.TextAlign = [System.Drawing.ContentAlignment]::MiddleCenter
    $dLabelWinnerStartLeft = 0
    $dLabelWinnerStartTop = ($dForm.Height / 2) - ($dLabelWinner.Height / 2) - $dLabel.Height
    $dLabelWinner.Location = New-Object System.Drawing.Point @($dLabelWinnerStartLeft,$dLabelWinnerStartTop)
    $dForm.Controls.Add($dLabelWinner)


# Config button control
# https://social.technet.microsoft.com/wiki/contents/articles/25911.how-to-add-a-powershell-gui-event-handler-part-1.aspx
    $dButton = New-Object System.Windows.Forms.Button
    $dButton.Size = New-Object System.Drawing.Size @(150,50)
    #$dButton.AutoSize = $true
    #$dButton.Dock = [System.Windows.Forms.DockStyle]::Bottom
    #$dButton.Anchor = [System.Windows.Forms.AnchorStyles]::Right
    $dButton.Text = 'PULL!'
    $dButtonStartLeft = ($dForm.Width / 2) - ($dButton.Width / 2)
    $dButtonStartTop = $dForm.Height - $dButton.Height - 50
    $dButton.Location = New-Object System.Drawing.Point @($dButtonStartLeft,$dButtonStartTop)
    $dButton.Add_Click({$env:dButtonPressed = $true})
    $dForm.Controls.Add($dButton)
    

<# Config text control
    $dText = New-Object System.Windows.Forms.TextBox
    #$dText.ScrollBars = [System.Windows.Forms.ScrollBars]::both
    $dText.Dock = [System.Windows.Forms.DockStyle]::fill
    $dText.Multiline = $true
    $dText.Parent = $dForm
    $dText.ReadOnly = $true
#>

$dForm.Add_Shown({$dform.Activate()})

# now we need to create a separate runspace so that the form can run on
# a separate thread...
$rs = [Management.Automation.Runspaces.RunspaceFactory]::CreateRunspace()
$rs.Open()

# create a variable in the new runspace that also points at the form object.
# We'll use the same name for simplicity...
$rs.SessionStateProxy.SetVariable("dForm", $dForm)

# now create a pipeline in the new runspace that will cause
# the form to be shown then close the input stream to the pipe since we don't
# need it and it will cause the pipeline to block
$p = $rs.CreatePipeline( { [void] $dForm.ShowDialog() } )
$p.Input.Close()

# Now start the pipeline running asynchronously
$p.InvokeAsync()

# At this point, the window should appear and we can start Writing stuff
# into the text box...
#$dText.AppendText("This is the first line we wrote!`n")
#$dLabel.AppendText("This is the first line we wrote!`n") # does not work


# magical variables
$dLabel.Text = ''
$dLabelWinner.Text = ''
$vUpdate = 'Clear'
$env:dButtonPressed = $false
$leverPulled = $false

$timeBeforeAutoClose = 60
$timeStart = Get-Date
$timeStop = $timeStart.AddSeconds($timeBeforeAutoClose)

$baseTextDelay = 225
$baseBlankDelay = 70
$scrollAcceleration = 1
$scrollSequence = (
    1.5,1,.9,.9,.8,.8,.7,.7,.6,.5,.4,.3,.2,.1,.1,.09,.09,.08,.08,.07,.07,.07,.07,.07,.07,.07,
    .07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,.07,
    .07,.1,.2,.3,.5,.7,.8,.9,1,1.1,1.5,1.75,4
)
$scrollState = 0

# Main loop
$running = $true
While ($running){
    # Update positions
        # Label (text)
        $fontSize = ($dForm.Height / 10)
        $dFont = New-Object System.Drawing.Font($fontName,$fontSize,$fontStyle,$fontSizeType)
        $dLabel.Font = $dFont
        $dLabel.Height = ($fontSize + 8)
        $dLabelWinner.Font = $dFont
        $dLabelWinner.Height = ($fontSize + 8)
        $dLabel.Width = $dForm.Width
        $dLabelWinner.Width = $dForm.Width
        $dLabelStartTop = ($dForm.Height / 2) - ($dLabel.Height / 2)
        $dLabel.Location = New-Object System.Drawing.Point @($dLabelStartLeft,$dLabelStartTop)
        $dLabelWinnerStartTop = ($dForm.Height / 2) - ($dLabelWinner.Height / 2) - $dLabel.Height
        $dLabelWinner.Location = New-Object System.Drawing.Point @($dLabelWinnerStartLeft,$dLabelWinnerStartTop)

        # Button
        $dButtonStartLeft = ($dForm.Width / 2) - ($dButton.Width / 2)
        $dButtonStartTop = $dForm.Height - $dButton.Height - 50
        $dButton.Location = New-Object System.Drawing.Point @($dButtonStartLeft,$dButtonStartTop)


    # Deal with button
    $buttonReady = (($env:dButtonPressed -eq $true) -and ($leverPulled -eq $false))
    If ($env:dButtonPressed){
        If ($buttonReady){
            $leverPulled = $true
            $raffleResults = Get-Winner -VerboseReturn -DoNotSaveWinner
            Write-Verbose 'Button works.'
        }
        $env:dButtonPressed = $false
    }

    # Change Text
    $vTakeAction = (Get-Date) -ge $actionTime
    If ($leverPulled -and $vTakeAction -and $vUpdate){
        Switch ($vUpdate){
            'Show' {
                $scrollSequenceFinished = ($scrollState -eq $scrollSequence.Length)
                If (-not $scrollSequenceFinished){
                    $vUpdate = 'Clear'
                    $dLabel.Text = Get-Random $raffleResults.OldLosers
                    $scrollAcceleration = $scrollSequence[$scrollState]
                    $actionTime = (Get-Date).AddMilliseconds(($baseTextDelay * $scrollAcceleration))
                    $scrollState++
                }
                Else{
                    $vUpdate = 'Clear'
                    $dLabel.Text = $raffleResults.Winner
                    $dLabelWinner.Text = '!! WINNER !!'
                    $scrollState = 0
                    $scrollAcceleration = $scrollSequence[$scrollState]
                    $actionTime = (Get-Date).AddMilliseconds(($baseTextDelay * $scrollAcceleration))
                    $leverPulled = $false
                }
            }
            'Clear' {
                $vUpdate = 'Show'
                $dLabel.Text = ''
                $dLabelWinner.Text = ''
                $scrollAcceleration = $scrollSequence[$scrollState]
                $actionTime = (Get-Date).AddMilliseconds(($baseBlankDelay * $scrollAcceleration))
            }
            default {}
        }
    }

    # Validate things and attempt to escape
    $timeExpired = ((Get-Date) -ge $timeStop)
    If ($timeExpired -and $lastTextTrue){$running = $false}

    If (-not $dForm.Visible){$running = $false}
}

# and finally close everything down - first the form and then the runspace...
$dForm.Close()
$rs.Close()