93 Lumina brake light on?

Does anyone have an idea why my brake light is on? Im not experiencing any problems...i recently did my rear brakes.

Are u sure the parking brake lever is fully returned to rest position (if it uses same lamp ) or that its switch is correctly positioned ?

The switch in the master cylinder could be sticking? Hows the fluid level in the master cylinder? What do your front brakes look like?

Im not sure i havent taken the time to look at the front brakes yet i honestly usually dont until they start squeal/squeakin...the brake fluid is good..

did you bleed the brakes after you worked on them?? I'm thinking that they may need to be bled. I'm not sure if that would cause the brake light to come on, but maybe..? I think there could be air in the system that needs to be relieved.

No to be honest i dont know how...i never did that on my Grand Prix and i havent had any problems....

All of the above are right.
NOw..in addition..you said you have changed rear brakes. Are these drum or disks?
If they are drums and you have changed the adjustment to minimal to ease installing the drum back, then it might need readjustment. If the adjustment is not tight and master piston travel is longer for the rear brakes than for the front disks, the sensor will detect "assymetrical" action and pop the light. I've seen that frequently.
To "auto adjust" rear brakes, you have to BRAKE HARD in REVERSE: this is the only time the adjustment acts. You must repeat that action several times, say 10 to 20: do not worry, once they are OK, they will not go overtight. If auto adjust was discarded, , then get under and tighten them.
Needless to say that if you feel mushy action on the pedal, you have air and it must be ousted first.