I've had good luck rebuilding my seat switches. Carefully pry off the seat shaped switches, then pry off the cover plate and "gasket" on top of the switch. Remove two screws and the switch can be removed from the housing. Once you have the switch out of the car, take out the screw on the back, and CAREFULLY open the switch (tiny ball bearings and springs might go flying everywhere). Clean up all the tiny bits with electrical contact cleaner and/or a small wire brush. Reassemble, and the switch should be good to go for another several years.
My 1991 is still on the original switches and I've rebuilt them maybe 2 or three times since 1996. Good luck!