Your brake fluid may be low or your brakes pads may be wearing down. I would have your brakes checked to see if they may need servicing. If that is the case, that may solve your brake light problem, if not then check the brake fluid level and fill that up to the proper level and see if that fixes the problem.
Hi Angie the warning light is brought on by the brake fluid level, 30,000 miles is quiet a bit of milage for your brakes they should be worn well check the fluid first it should be low. Check the pad and shoe thickness and also the seals for signs of leakage and remedy as nessesary.