Sometimes it is necessary to stack controls like doors and switches over each other. If we would like to edit them, we first have to change their position on the level. This is a source of errors. If we forget to return the controls to their original places afterwards, the functionality is broken.
A better way would be to have a way in order to select another control on the stack without changing the position of the first control. How about to solve this by a double click or a middle mouse button (mouse wheel) click on a stack of controls?