Demonstrating an alternative to `async void` event handlers. Both print out messages in the order listed (1/2/3/4). Also, if you remove the Sleep(), neither prints out #4 because the process exits first.

async void event handler.cs

static void Main()
{
    MyEvent += Handle;

    Console.WriteLine("1. Before invoking event");
    MyEvent(null, null);
    Console.WriteLine("3. After invoking event");
    Thread.Sleep(1000);
}

private static async void Handle(object sender, EventArgs e)
{
    Console.WriteLine("2. Start of handle");
    await Task.Delay(500);
    Console.WriteLine("4. End of handle, after await");

}

static event EventHandler MyEvent;

non-async event handler and ForgetTask().cs

        static void Main(string[] args)
        {
            MyEvent += Handle;

            Console.WriteLine("1. Before invoking event");
            MyEvent(null, null);
            Console.WriteLine("3. After invoking event");
            Thread.Sleep(1000);
        }

        private static void Handle(object sender, EventArgs e)
        {
            HandleAsync().ForgetTask();
        }

        private static async Task HandleAsync()
        {
            Console.WriteLine("2. Start of handle");
            await Task.Delay(500);
            Console.WriteLine("4. End of handle, after await");
        }

        static event EventHandler MyEvent;
    }

    static class TaskExtensions
    {
        /// <summary>
        /// Suppresses warning CS4014 ("Because this call is not awaited, execution of the current method continues before the call is completed.") and makes it obvious that you didn't want to await the call.
        /// </summary>
        public static void ForgetTask(this Task @this)
        {
        }
    }

non-async event handler.cs

static void Main()
{
    MyEvent += Handle;

    Console.WriteLine("1. Before invoking event");
    MyEvent(null, null);
    Console.WriteLine("3. After invoking event");
    Thread.Sleep(1000);
}

private static void Handle(object sender, EventArgs e)
{
    HandleAsync();
}

private static async Task HandleAsync()
{
    Console.WriteLine("2. Start of handle");
    await Task.Delay(500);
    Console.WriteLine("4. End of handle, after await");
}

static event EventHandler MyEvent;