Those small revolving lights usually use a small 3-6 VDC motor (plus the light) to run them. Probably the easiest way to turn them on and off would be to use a relay circuit (plenty of info for that all over this forum, in the playground, on the internet, etc).
You could also drive it with a "large" power transistor or MOSFET; anything that can sustain 1.5-2 amps of current draw should work OK (but measure the current draw first just to be sure).
Great! Thanks, I actually did some more crawling through the forums, and think that maybe i should use a transistor in the light's switch, and let the wall power or the direct USB power them.