Darth Lars said:
If you want to make something that looks like an arc between two fingers, then you could use electroluminescent wire (EL wire), which is a glowing type of wire. You could use makeup to hide the electrodes going up your fingers.
EL wire also runs on very high voltage, but at low current and can be fully insulated so I think that it could be much safer than a real spark. You need a driver (called "inverter") for it.
There might be some old threads left about how to make lightsaber blades with EL wire.