Mine, which was on the car when I got it, fits into a small metal box which mounts under the dash using a single screw. The wiring is such that when the switch is on, it connects together the circuits for the parking lights on both sides, and a flasher, separate from the normal direction signal flasher.
My switch is not as sturdy as I'd like it to be, so if anyone has a source for a better hazard light switch I'd be happy to hear about it.
Chris