Idea:

A metal electrical box key will cost a couple of bucks, so I decided to make a 3D printable one which costs around 10 cents a piece and can be printed in under an hour.

I designed this key to be strong, even when printed with PLA, it can be printed fast, without supports and can open pretty much all standard electrical boxes.

Important note:

Might have to scale the model up by a couple percent if the fit is too tight, also I recommend printing with 100% infill and 0.2mm layer height or lower to make the print as strong and durable as possible.