Idiot light for the e-brake is a separate light...to let you know it is 'set'. And it does have a habit of getting stuck. Older YJ's (like mine) it's on the footpedal for the parking brake and the pedal is screwed up so you have to kick it sideways to shut the light off.
Brake system fluid level is a different light/indicator and is very sensitive. You can be just a tad bit low in only one side and it will kick on, or if you are out wheeling and go off camber on a good tilt, it can trick the light into coming on. Level off on the ground-it goes out. Just means it's time to top it off a bit. I have to top off mine once a year, had the calipers, rotors, etc. all replaced and thought that would fix it. No sign of any leak anywhere but it still goes down just enough for the 'off camber alarm'...LOL...(on my 03 rubicon)