I am about to rewire my printer with dual switches, kind of like the light switches at either end of a hallway, or at the top and bottom of stairs. Right now I have three physical switches on my printer, one for main power, one for lights, and one for X, Y, and Extruder motor fans. I have some SPDT switches on order to replace these three switches, which I'm going to hook together with a relay board controllable from the RasPi. This way I can control the power, lights, and fans when I'm at the printer, or I can control them when I'm away over OctoPi. I could flip a relay through the webpage to turn the lights on, then flip the switch on the printer to turn them off again, and vice-versa.