CodeBehind.xaml

<ListView IsItemClickEnabled="True" 
          ItemsSource="{Binding Items}" 
          ItemClick="OnItemClick" />

CodeBehind.xaml.cs

public ViewModel ViewModel
{
    get { return DataContext as ViewModel; }
}

private void OnItemClick(object sender, ItemClickEventArgs e)
{
    ViewModel.ItemClicked(e.ClickedItem as string);
}

ViewModel.cs

public void ItemClicked(string item)
{
    // react to the event
}