2008 Saturn Aura Brake lights stay on while driving

Recently, my brake lights have come on while driving and stay on. I drive my car 4 times a day. To work, home for lunch, home from work and to play tennis. They generally only come on during the late afternoon and evening. Never in the morning.

Check my fluid, it's good. Replaced the switch relay. I don't know what next.

Any help is greatly appreciated! I'm trying to avoid paying the dealer an over the top amount.

Hal D. Cottingham