I just had a new shower put in, and the existing carpet doesn't quite go close enough to the bottom of the shower. It looks uneven. Is there something I can buy to make it flush?
Ignoring the fact that carpet in a bathroom is just a bad idea, I see two options:
Install a threshold to cover the gap
You might be able to put down a new tack strip and stretch the carpet. This will really depend on how large the gap is (you didn't say)