I do agree that it's worthwhile checking the brake light switch for sticking. Zero cost and easy to do. Just get out and walk around the back. Or back up to a white wall and press the brake a few times, see if it ever stays on. Try the cheap and easy stuff first.
Note that OP has lenses that ABSORB LIGHT (which I will never understand) and they almost certainly ABSORB HEAT too. They tend to go together.
Engineers do it with a torque wrench