Step 7: Manual power supply
In the electrical section at Home Depot I picked up a light switch, a cover, and a blue plastic conduit box. Total cost was less than two dollars. The 4xAA battery pack I already had.
I had India help me with the soldering and assembly for this part, it was pretty straightforward and she had fun helping out. Basically, instead of wiring up the automatic circuit as an interrupt in the positive wire from the battery pack, you wire up the light switch. A basic single pull single throw light switch has three screws in it, two on one side which you'll attach your positive wire, and one on the other side that I'm assuming is for ground when you're actually doing home wiring. It's painted green and you can ignore it.
After the switch is wired up, glue the conduit box to the battery pack and attach four strong magnets to the back of that. All done!