When stepping on break light goes on in dash board

When you step on the brake pedal, have someone stand behind the car to see which brake lights light up and which ones don't. I am assuming you are seeing the brake failure lamp on the dash light up - and not some other light. Once you have identified the lamp that doesn't light up, I would suggest identifying the bulb number in that position (left, right, center Cyclops in the rear window) and use your owner's manual to purchase the correct bulb. The owner's manual for that year and model SHOULD tell you how to access the bulb easily, and then replace it. Hope this helps.

Sounds like you have a short in the brake light circuit. Get a professional to look at it as this may indicate something more than a nuisance.