I will need to update later with the actual print with it in use.  I forgot to take a picture, sorry!

This is for those weird times when the double gang box you are using has screw locations for both sides of the box but not in the middle and you only want to use 1 outlet…

The local big box store didn't have double gang covers that has the outlet offset on one side and solid on the other.  Yes, I could have designed and printed a custom cover, but I already had the double gang, double outlet covers.  

There will always be reasons to not do this, but sometimes it just feels right, ya know?

This is modeled after a standard US 110v outlet.  I have printed this and installed it.  It fits great.  

Print settings: (use what you like)
PLA
.2 layer height
4 walls
3 top and bottom layers
15 - 25% infill
supports needed for the mounting ears only

I also added a cylinder modifier when I sliced it to the center screw area so I could make it solid with walls.  This way, if you want to run a tap for the screw threads instead of cutting them with the cover plate screw, you can.