1992 Dodge Spirit Brake Lamp out

In warm or hot weather only. I keep getting a "BRAKE LAMP OUT" alert. I have tried replacing bulbs but nothing works. I've replaced the actual light socket with a brand new one but still the problem exists. There is electrical power to the tail light and it comes on fine. The bulb is a 2 filament bulb. The Large taller filament is the tail light, it works fine. The shorter filament is the brake lamp filament, and it is the one not receiving power. Once again, this is only during warm or hot weather temperatures. In Cold winter temperatures, both brake lights work fine. The left tail light assembly works fine all the time. Could this be in the brake pedal switch itself??

Thanks

Eric