Red Brake Light

Hi, I have a 99 Grand Am and recently the red brake light came on in the dash. I checked my brake fluid and the emergency brake and everything looked good. My brakes seem to be fine. I know that my abs harness needs to be replaced for months now but my brake light never came on until now. Yesterday when I was driving the brake light, abs, and traction light was going on and off and then eventually stayed on. Does this sound like a sensor problem? Emergency brake problem or Leak some where? Thanks in advance. :)

If the ABS light is on the red brake light will also come on

low on brake fluid, check for leaks.

if day time driving lights work then e-brake switch is ok.