2004 Ford Expendition Brake Light Issue?

I have 2004 ford expendition. My brake lights were working and now they aren't all of the time. I have checked both of the brake fuses. I changed the second large fuse in on the top of the panel, since the auto part store said that is the fuse that controls the brake lights. The lights came on and then went off. I checked the light bulbs, and they are okay. The lights are going on and off. I never move the steer wheel up or down. What may cause this problem.

The brake light switch mounted above the brake pedal is out of adjustment, simple 3 minute job