Deselect a Listbox

Try something like this....

Change ListBox1 in the following code as per the name of your ListBox.

Private Sub ListBox1_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Dim i As Long
For i = 0 To ListBox1.ListCount - 1
   ListBox1.Selected(i) = False
Next i
End Sub

What is the Name of your ListBox Control?

Then try this. The code below will deselect all the selected items in the ListBox4 after double clicking the listbox.

Private Sub ListBox4_DblClick(ByVal Cancel As MSForms.ReturnBoolean)
Dim i As Long
For i = 0 To ListBox1.ListCount - 1
   ListBox1.Selected(i) = False
Next i
End Sub

For a listbox from the Forms menu, assign it to this macro

Sub ListBox1_Change()
    Static flag As Boolean
    If flag Then
        ActiveSheet.Shapes(Application.Caller).OLEFormat.Object.ListIndex = 0
    End If
    flag = Not flag
End Sub

Ah I missed that it was a form control though the OP mentioned that. My bad.