Step 1: Get your stuff together...
An LED electronic candle (flickering tealights)
A plastic hand - IKEA Patrull safety bumper caps
Pin backing clasps - found in the jewelry findings/notions at the craft store
Hot glue gun to put it all together
Hacking tools like a utility knife, screwdriver, wire cutters
CAUTION: Know how to use your hot glue gun and handle hot glue only when cooled or you will burn yourself.
Step 2: Hack electronic candle
The battery, switch, and LED are all in one unit. Bonus is that it flickers so it animates the light a bit. Only drawback that it is a bit dim so it doesn't really light up the thick translucent plastic hand. I guess you can switch out the LED for a brighter one.
Crack open the electronic candle by prying open the cover. Insert a utility knife in the seam to crack open any glue. This one is held together by a post and mating post on each side of the case. It is snap-together construction so it is easy to pull apart.
I also pulled off the silicone "flame" diffuser. You can use it if desired but I only wanted the small bare LED.