*New link in comment #1*
Go on, Buy one for every light switch in your house ;)
2x made to order High Quality Star Wars Light Switch Vinyl Decal Sticker in either Black, White, Green or Pink. 1x Light Side (Yoda), 1x Dark Side (Vader). You can position them however you like on the light switch, depending on which side you turn on/off the lights.
The size of each sticker is approximately 2.5cm in Height x 5.5cm in Width and are made from a very high quality weatherproof vinyl.
Cheaper price in the comments - read before you buy. Wish I did :/