I meant to upload these designs back when I made my lightswitch covers and forgot to. I was recently reminded to do it, so here they are:
The green area is for engraving a well for the tiny tiles, so if you don’t have those just ignore the operation. The brown lines are score lines just to add interest–you can substitute whatever you like for those.
Almost forgot: if your switch hardware requires a bit of a hollow behind the switch to hold the electrical guts, here is a piece you can attach to the back (I had to for the smaller switch), make it out of veneer or 1/8" plywood. I didn’t need one for the larger switch so you’ll have to make your own.
Edit 3/14/2019 (Pi day!): adding the double switch cover file that I used for my living room, posted here.