87 Honda Civic Si HB Brake lights dont always work, any ideas?

My brake lights work when they want to and I have already checked the fuses and had the wires checked. The garage checked my wiring harness and said it was good. But sometimes they work and sometimes they don't. Anyone have any ideas on whats causing this and how I can fix it?

Could be the switch above the brake pedal getting lazy or a poor connection to that switch.good luck...and welcome to the forum!