I have a 2002 EX V6 and the brake light stays on for awhile on cold mornings. As soon as the car heats up it goes off. The brake fluid level is fine. The only 2 things that I know it could bewould moisture in the master cylinder sensoror the emergency brake swith. It has 4 wheel discs and the brakes work fine.

 

The first thing I suggest is to actually remove the master cylinder cap and visually see the fluid level.
Often times there are sediment lines on the inside of the reservoir that can give the appearance of good fluid level.

Second thing you can do, when the brake light is on and engine running, remove the master cylinder cap and flip it upside down to let the float slide to the cap, then check if the brake light is on/off.
With a multimeter you can check for continuity when the float is up to the top of the slider,

 

Thanks, I'll give that a try