Light will go out when you replace the bad sensor. I melted a sensor coming down the hill into turn 10a at Road Atlanta and my brake wear light came on, got my heart rate up...
If you pull the brake pad wear sensor end out, you will probably see that one of them is melted into a blob, and that is probably the bad one, and is 99.999% one of the fronts.
I don't run any sensors anymore, I clipped about 1" from the end that connects to the wheel carrier, stripped the two wires, twisted them together and insulated them, and I just check my pads visually. Since I have the wheels off all the time due to track work and brake bleeding, it works for me
I've actually got an extra sensor I can send you if you PM me your address. IF I can find it... It was only $5 or so from R O C K A U T O . C O M.