What wire supplies power to my brake light and how do I fix it?

You will need to trace the power wire back to find an open. Alex

I'm going to say a little more electrical testing is needed here before you rip apart the car. If you aren't familiar with wiring on a car here is a link to find a shop near you that can help out. https://repairpal.com/questions Alex

Your car is equipped with a "Lighting Control Module". It takes the input from your turn signal switch and brake switch and then turns on the appropriate tail light. There are 3 fuses that power that module. Fuse 1 (30A) and Fuse 5 (20A) in the power distribution center and are hot at all times. Fuse 19 (10A) in the "Junction Block" (In the cabin?) that is Hot in Run and or ACC. The most likely cause is one of those fuses or the module itself.

Do you have a 12 volt test light??