What is your budget like? The first thing that comes to mind for me is getting a cheap dustbuster hand vac. You might be able to find one at a thrift store too. Just glue or mount a dial and a piece of red plastic on it for the screen. The bulb would be a bit harder. If you can find a plasma globe that would do the trick, but it would be round, and might be hard to come by in short notice. It would also add at least $20 to the prop cost, most likely. But it would be the best looking. Alternately, hit the thrift and dollar stores again. Find a cheap plastic glass and some neon yellow paint in the craft department and paint the sparks on. That would be the cheapest but least attractive way to do it. You might be able to find a lighting kit at a hobby store near you. Combine that with the plastic glass for a better look.