The cans at the bottom appear to be standard low voltage lighting control relays. Those are usually dual coil latching relays--one coil is pulsed on to turn the lights on, and the other is pulsed to turn them off.
The enclosure may be homebrew (not even sure about that), but that PC board sure isn't. There should be a manufacturer's name or model number on it somewhere, and a Google search might find info on it.
The input and output wiring, while messy, should be easy enough to trace out once you have an idea how the PC board and the relays function.
Last edited by NJwirenut; 02/14/08 08:20 AM.