Wiring Multiple PCBs Into 1 Stick

I’ve noticed more and more arcade sticks popping that are compatible with multiple consoles with the flip of a switch.

My questions are:

How is this wired so that one switch can effect all of the buttons and each PCB?

Or is it just a matter of switching which controller is powered?

You’re talking specifically about the PS3/Xbox360 jobs. Read up on these threads

NO! Bad idea. Read those threads. All PCB’s MUST be powered at the same time.