Tailights Are On

Lets do so basic troubleshooting. With the ignition switch turned off. Fuse marked brakes is one of very few hot at all times. Remove that fuse and see if the rear lights are still on. If they are the problem is in the wiring.Check for power at the brake light switch. Should be none.
If the brake lights went off when fuse was pulled, put the fuse back and check the brake lamp switch with a test light. There should be power on only one of the 2 wires there. If both wires are hot the switch is bad. Let us know your results and we'll proceed.