i've built a parallel 12 controller.
12 relays 5V switching 120v@1A
12 "2222" transistors
parallel printer cord
12 extension cords
and you def need a inline fuse
wire, electrical tape, soldering iron, solder, and the largest project box from radio shack.
they are coil relays, so it's on/off no dimming, plus you'll hear little mechanical "clicks"