I discovered today that my brake lights(both of them) arent working.

I have checked the fuse, which is ok. I have not checked the bulbs as yet, but whilst its both lights that are not working, my guess is that its not that simple.

I am guessing it could be the switch thats failed, where would I find this on a 1988 4/4 4seater?
Any other ideas as to possible issues gratefully received!