I don't think they fake anything, but I don't think they ever find anything convincing, either.

That ambient sounds thing they do (called EVP, my daughter reminds me) shows some strange sounds now and then and often shows nothing to listen to at all. I think it proves conclusively that if you record for hours and hours, then you sometimes capture odd sounds that sound like voices.

They investigated a motel/restaurant/bar last season where the owners were definitely trying to hoax them. The investigators found the equipment, but the owner said it was there from before and they forgot about it, or something weak like that.

It's mostly a background noise show for me, while I'm doing something with my pc.