1996 964, 91.5k miles

The problem is simple, but it could be disastrous in traffic.

When I press the brake pedal, the brake lights do not *always* come on. I noticed this just last night while driving home. Those big chrome bumpers on SUVs are good for something afterall!

This is not dependent on how far I push the pedal. When they're not working, they're not working. I don't know much about electrical systems, but I'm guessing that there is a switch that is malfunctioning. I don't think that the problem is a bad fuse, since the problem is intermittent.

Is there a switch somewhere that I can get to and replace. I really don't want to take it to the Volvo dealer or an electrical place, because both will want to run a bunch of pricey diagnostics for what is probably an easy-to fix problem. (PLEASE tell me it's easy to fix, or at least cheap!)

Please help! I think it's only a matter of time before my "rear-fog-light-as-a-manual-brake-light" technique will fail and I get rear-ended!

Thanks in advance for any tips/advice/repair techniques.