Single Gang Electical Box Extender

Single Gang Electical Box Extender for North America.  I designed this as one of my boxes was too deep in the drywall, so designed and printed to suit my needs.  You can adjust your Z height in your slicer software to get the size you need. (make sure to only change your Z height)  

Edit - As noted by user @stimmenhotel, PLA might not be legal to use in an electrical box.  With this knowledge, I'd recommend to NOT use PLA except for maybe a test print, but something like ABS might be more appropriate in this instance.

Depending on the manufacturer of your electrical box, you may have to fine tune this to work in your particular instance.