One of my mates used to live in a house they believed was haunted. They got a spiritualist/paranormal investigator/fraud out to the house to sort it out and he said that there appeared to be a portal where the fireplace was letting in spirits.
So he charged them, closed it and went home and my mates family carried on with their day, thinking everything was sorted when they were woken up by a phonecall in the early hours from the spiritualist guy.
He rang up panicked to tell them that he had actually forgotten to shut the portal in the fireplace and has to come back to shut it. So basically his job is imaginary and he's still awful at it.