How to add a Click event on a CheckBox Listbox in Powershell WPF?

I'm looking for a way to add a click handler inside a CheckBox Listbox in Powershell WPF.
I need to pass the checked items in the listbox to an array variable whenever any checkbox gets checked/clicked.
Is there any click/mouseLeftButtonUp invocation method I could use on the ListBoxItem? I've found isMouseCaptureChanged and PreviewMouseDown, but they only work when I click off the checkbox item (cant check the box perse).

To add more context:
I'm trying to make a CheckListBox of the C:\Users folder where you can select multiple users and then pass it to a variable to run a profile backup command.
This is the code I have until now:

This is the WPF of the CheckBox ListBox:

<Grid Margin="5">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <Label Grid.Row="0" Content="Users to backup:" Foreground="CornflowerBlue"/>
    <StackPanel Grid.Row="1">
        <RadioButton Name="rb_AllUsers" Content="All users" IsChecked="True"/>
        <RadioButton Name="rb_Users" Content="Selected users:"/>
    </StackPanel>
    <ListBox Grid.Row="2" Margin="5" Name="lb_Users" ScrollViewer.VerticalScrollBarVisibility="Auto" IsEnabled="False">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <CheckBox Content="{Binding DisplayName}" IsChecked="{Binding bChecked}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Grid>

And this is what I have as handler by now (not working as intended):

$window.lb_Users.Add_IsMouseCapturedChanged({
    if($window.lb_Users.SelectedItems){
      Write-Host $window.lb_Users.SelectedItem
    }
})

(note that the Write-Host is only for testing purposes)

Also tried with PreviewMouseDown:

$window.lb_Users.Add_PreviewMouseDown({
  if($window.lb_Users.SelectedItem.bChecked -eq $true){
    Write-Host $window.lb_Users.SelectedItem
  }
})

In this case I can check the item, but it only shows where the listbox index is.

What I'm looking for is to select multiple/single items in the CheckBox ListBox and pass it/them to a variable. Is there any handler for the listbox item?

EDIT:

Found a workaround about the Check ListBox and now I'm using a stackpanel with togglebuttons, I add the users's buttons by creating them via code when the script runs and I added a general handler for them when they are checked:

$users | ForEach-Object{
  $user = $_.Split('\')[1] # Here I split the domain of the user and take only the username
  $newBtn1 = New-Object System.Windows.Controls.Primitives.ToggleButton
  $newBtn1.Name = $user
  $newBtn1.Content = $_
  $newBtn1.AddHandler([System.Windows.Controls.Primitives.ToggleButton]::CheckedEvent,$tbhandler)
  $newBtn1.Margin = 2.5
  $null = $window.sp_Users.Children.Add($newBtn1)
}

And here's the handler for those ToggleButtons:

[Windows.RoutedEventHandler]$tbHandler = {
   Write-Host 'Test'
}

I want that handler to print the button's name or content when is checked so I can pass it to a variable to update it on the GUI.
Any way on how can I do so?

Try to handle the ToggleButton.Checked attached event for the ListBox.

I believe it should be implemented something like this in Powershell:

[System.Windows.RoutedEventHandler]$handler = {
   ...
}
...
$window.lb_Users.AddHandler([System.Windows.Controls.CheckBox]::CheckedEvent, $handler)