2003 300M E Brake Light
 

I recently purchased a 2003 300m and the Dash E Brake light is coming on. The brakes feel great, no spunge, no pull, they feel perfect.
The fluid is NOT low, the pads are new, the parking brake is fully released.
I can find no pattern to the light coming on and going off.
The used lot did tell me they replaced the master cylinder a few months ago.
Any ideas what to check or replace?
thanks,

see if the sensor under the master cyl is plugged up all the way

Fixed
 

Kevin,
that was the area. The sensor feels seems loose in the master cylinder, but i am not sure how it is fastened in (threaded, twist lock ??) any how i wiggled it around, disconnected the connection started the engin and the light was out. Pluged it back in restarted the engine and the light was still out.
Thanks for your help!:)

welcome