I know that this is a hack which allows a LED to run in half wave rectification and light up a standard wall switch. There is a small amount of voltage and current always running in the circuit unless the load is burned out.
Check with local regulations before using this switch. Since this is not CE certified it may present a safety concern. I have had no problems but I assume responsibility in my own home. Play safe and have fun.
You can choose to light one side of the paddle or both.
Step 1: You will need
6.2 KOhm Resistor 3Watt
A diode 1N4007 works nicely.
A couple of LEDs. Unfortunately I used Blue.
Step 2: Disassemble and prepare the switch
The white paddle is in two parts and when warm can be pried apart easily.
Inside of the switch body are 3 parts. There are two stationary sections and a third movable section. Make note of how the parts work and disassemble.
You will need to solder a short wire to each of the stationary sections.