Here are the steps how I did the switch covers
To begin with, you need a switch cover (of course), little fabric, a pen, glue gun, scissors, a screw with a sharp end (or anything sharp, e.g. pin or nails)
1. Cut a piece of fabric just little bigger than the switch cover
2. Draw the shape out using a pen or pencil
3. Cut the shape out, also cut the diagonal to the corner (see picture). When cutting the shape, leave some space so you could glue to the switch cover.
4. Start putting them together. Line the cover with the fabric using the shape you drew.
Make sure you pull the fabric tight enough when you glue them onto the switch cover.
5. Cut the corners off
6. Glue each side onto the switch cover
7. Almost finish
Finally just use a sharp screw or nail to make the holes for the original screws, now it is ready to put it back on the wall.
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