Aircraft safety wire works OK. If you can't cop a few feet, it's an investment to buy a whole one-pound spool.

For a buck and a half, you can get stainless steel fishing leader at Walmart. It's thinner then safety wire, and straighter. Safety wire is full annealed. Fishing leader is hardened and much less curly than safety wire.

For a power supply, I used a radio-shack 6V power transformer, a ceiling-fan variable speed control, and a toggle switch. The ceiling fan speed control will take the inductive load of the transformer, where I feared thet a lamp dimmer, which is designed for resistive loads, would not. The components are all stuck together in a radio-shack project box, with long wires and alligator clips to connect to the hotwire.