This circuit is based in a simple non-stable multivibrator, feeding its output to a power transformer.

This circuit works with +6VDC power (4 "AA" Batteries). This circuit can be used to light fluorescent lamps up to 50W using a 220VAC transformer instead with its secondary coil directly to the lamp’s terminals.

You can also have fun using it on people, I do!!! But be careful for this may be dangerous in some people.