All my brake lights just stopped they worked last night and just stopped

Hello, It sounds like you are experiencing a wiring issue, or an issue with the body control module. I'd have to look at wire diagrams for a little while to find out if all of the rear lights run through the body control module, but in the absence of any issues inside the vehicle, it seems related to wiring. Of course, it is a good idea to check the fuses for the rear lights, but ultimately, if the fuses are good, the vehicle will need diagnosis to prove the issue. If you are going to tackle the issue yourself, I can help out with information, but if not, see one of the certified shops from this link: http://repairpal.com/cadillac-within-10-miles-of-modesto-california-95354