That would require rewiring them quite considerably though - you would need them to run soley off the mains for that. The way to do it would be to rewire only the wiring between the momentary switch and the sound board (or replace the switch on a stunt) and have it so that you add in a wireless recieve, something like a radio reciever or sorts, and then use the remote to turn it on and off.
Chances are you'd have to make your own radio reciever as youd be hard pressed to find one small enough 'off the shelf' to fit inside a hilt, but in theory it should be fairly simple once you have the parts.. It would literally just act as the switch for the saber.
