Help with lights...reverse, brake & signal

My reverse lights work when they want... Sometimes I have to put the stick between p and r to make it work. My signal and brake lights don't work at all. I've changed the fuses, the brake light switch and the signal flasher but still no luck... Suggestions please anyone before I get a ticket?

and your car is?:D

Have you used a test light at the brake light switch to see if you have power after the switch? If you do, check at the rear of the car to see if it makes it there. If it does and the lights don't work than it is most likely a ground problem.