'01 Jimmy with crazy electrical problems

So I was towing my boat back from the lake and noticed that the tail lights were brighter than usual. I pulled over and checked it out and it appeared the brakes were pushed when they were not. So kept driving and the cruise control would not work, due to the fact the car thinks the brakes are being applied. I got to my exit and went to use the right blinker, and it lit up on the dash, but just stayed on. The left blinker works as fine. So I decided to see what the hazard's would do and all blinkers worked and the brake lights reset themselves and the cruise control worked. But like a minute later brake lights back on, sticking right blinker. I get home and disconnect the trailer thinking that it may be the problem. I get back in the car and without the key in the ignition I press the brake pedal and the dash, radio and headlights all come on. It acts like the key is placed to the "on" position when you push the brake pedal. So any ideas?

New edition. I have a CEL with a code of P0740. From what I have been reading an ignition switch can cause this problem. Could that switch be causing all my other troubles? There appears to be nothing wrong with the transmission when driving.

Multifunction switch fixed everything if anyone every has a similar problem.