I love skeptics.
I wasn't a huge X-Files fan (gasp!), but I admired Scully's conviction as a skeptical scientist that everything was explainable. She could've been bitten by a chupacabra while having a conversation with Bigfoot in an alien spaceship and still would've been able to explain it all away.
I know that's an extreme example, but I think skeptics are a good thing. I mean, someone has to be the voice of reason, the control opinion to the unexplainable. As a ghost hunter, you encounter some pretty unusual things, but also things that often really are the knocking of pipes, the rustling of leaves, the sound a ceramic pot makes from the vibrations of the floorboards, drafts--you name it. Using your own inner skeptic helps to keep you on your toes thinking. Not everything is paranormal...
...yet not everything isn't either.