This is an outlet box extender for household outlet boxes that are too crowed for larger switches or receptacles. I purchased a smart switch but realized the outlet box was too crowded with wires to fit this larger bodied switch. So a designed and printed an extender to hold the switch outside the box. This was made to match the face plate that came with the Gosund Smart Light Switch. The size of this face plate is NOT a standard US size. It extends the switch 1.25 inches from the wall. I used two #6-32 screws that were 2 inches long to attach the switch and extender to the wall box. I image this would also work well for GFI's.

Note: I made an extender that is sized for standard switch face plates: https://www.thingiverse.com/thing:3225261