Well, part of the problem here is when someone views him/herself as having authority to deny claims of the paranormal with certainty. "Ghosts don't exist because I haven't seen sufficient evidence to support their existence."
One wouldn't apply that "logic" to anything in the natural world. If you have never run a marathon, you would take the advice rather quickly of people who have run marathons, as to how to train for one. Yes? But, with the paranormal, skeptics don't take the evidence of those who study possible paranormal events, for a living. The skeptic becomes the authority, with certainty no less, simply because he doesn't wish to believe in it.
Things that make you go...hmmm.