1999 Cadillac Escalade brake dash light

First is to identify what is causing it. It is controlled by the daytime running lamp module, with inputs from the park brake warning switch, and brake pressure warning switch(via the EBCM). First and easiest to rule out, find and disconnect the park brake switch, if the light goes out, that is your problem. There is a little copper tang that can break, and the closes the switch until repaired. If you have no abnormal braking problems, and the hydraulic system has not been opened up either by bleeding, part replacement, or a leak, there is no reason to believe it is a brake pressure switch, yet.