Can I fix a short at home?

My Olds. Silhouette is haing issues with the tail/brake lights. We have checked all fuses and replaced ALL bulbs, even in the front, and are still having problems. When you press the brake, both turn signals light up on the dash, however are steady and do not blink. Since this has happened, I have had no rear lights at all, with the exception of the brake light on the hatch. The Hazard lights DO work though. I'm thinking we have a bad ground someplace. Can we fix this without having to go to a mechanic? Thank You.