Brake lights
Hello
I have seen this problem for many times.
Remove your brake light socket and check the contacts. usually what happens is that the brake light bulb melts the plastic socket and it covers the contacts. you can try to fix the socket but if not you will have to buy new one. Its about 5-6 dollars maybe even less. I hope i did help your problem. please let me know if anything else will come up.
Sincerely, BMS tunner