>>5746359Battery operated I presume? You have some options. There's some kits with wires and a button out there but you have to solder the wires yourself, alternatively you can go with a cheap dollhouse bulb that will run you maybe $9 on EBay which you can paint over with clear green paint.
Cheapest option would be a green LED tea light on right. It's a primitive twist to open and turn on but at $5 for 5 it's a very affordable option.
