I bought a electric cutout without a switch,what else can I use to work it?

 

Any 12v (I think) momentary switch. Go up to radioshack and get one for like 5 bucks. You could even use a factory fog light switch as well.

 

You want a momentary 2 Position rocker or toggle switch.
Trying to remember if you need a SPST, SPDT, or DPDT, DPST style. It's been so long since I messed with electronics and switches.

here is a crude wiring diagram I just made,