if your brake lights stay on without pushing the brake pedal down.....it is your brake switch that is eather loose or faulty.....
I had the same problem...and had to replace it on my 96 ZJ...
it works no problem now....
you have to remove the bottom under the srearing....has few screwes....and you can then acces it easy,....it is a plug and play type part...where you disconect the harness of it....then turn the switch to pull it out...and same way to install it back....and the part is self ajusting as well....takes 15 min and 1 screwdriver...