rear fog lights not working.

My rear foglights have never worked since i bought my car,so far ive checked the fuses and the bulbs (is there only 1 fuse for both front & rear fogs but seperate switches for both?), is it worth buying a spare rear switch from a breakers to see if that fixes the problem or any other suggestions as im shi ite @ leccy?

To test if it's the switch I'd be tempted to use a multi-meter at the switch terminals to check you get continuity when it's turned on. Then just disconnect one wire from the back of the switch and connect directly to the other so it's physically made the connection, effectively by-passing the switch and should test the wiring to the lights.

Then check the fog light to chassis connection, remove, clean, re-make the connection.

I'm sure you know they only work when the head lamps are on and they are tested at MOT time.

Bypass the switch and try again other than that fuse or bulbs, the bulb connectors are normally ok as they are away from any dampness but still could be iffy.
It the other rear lights are functioning ok then you know the earth connections to the two lamp units is ok.