I made this to cover light switches for lights that are being controlled by a home automation system. It functions to stop people from flipping the switch off which disconnects the light from the system. It also removes the visual noise of the switch from view.
Measuring Your Light Switch
Measure your light switch as accurately as possible, in millimetres. There is 1 mm of wiggle room built into the design so you don't need to add anything to your measurements. However, always round up with your measurements because it is better the cover be a little loose than too tight.
When measuring the base depth, make sure to include the depth of the screw if it sticks out beyond the plate.
Settings the switch depth to 0 would produce a cover suitable for a wall outlet or internet outlet.
Glueing in Magnets
I used epoxy to glue magnets into the magnet holes.
I painted the cover first using a spray-paint primer meant for use on plastic, followed by two coats of the paint used on the wall behind the switch, to match.