Here's a guitar I built a few years ago.
. With a couple of SD hot P-90 pups, controlled with phase and serial/parallel switches it's a hot mama. Just one thing to keep in mind: When using a ganged switch/pot - use the tone, and not the volume controls. Because if you use the volume control, when you engage/disengage the switch you momentarily short the pot. Guess what happens if that pot happens to be the volume pot? And no, the pot doesn't smoke. What kind of voltages do you think we're dealing with here?