Signal-Brake lite issue

Have you check the brake light switch at the pedal. You may have bumped it when you
changed the carpets. The brake circuit runs through the flasher and the flasher switch.
Are your tail lights working if so it's not a ground they wouldn't work if there was a bad ground at the bulb. That is if you don't have separate bulbs one for brake and one for tail light.
You didn't say what car your working on.

As someone said in another thread " some people have more then one car" so we can only guess. So everybody when asking for help please let us know what vehicle you are asking the question about.