Park break light stays on sometimes

The parking brake warning light also serves as a brake fluid low light. Check your brake fluid level, it might be just a little shy of the low mark which will cause the intermittent condition. Use the appropriate fluid (DOT 3 or 4) and don't fill to the full mark or the next time you get your brakes serviced it will be overfull. Also, check your brake lining thickness, as the pads wear the fluid level drops in the reservoir.

Check the parking brake light switch which is located under the center module, remove the cover around the parking brake and you'll find it there.