They spend a lot of time in darkened basements using instruments like electromagnetic field meters, night vision goggles, and Geiger counters.

Some call them ghost hunters, but they call themselves paranormal investigators of the unexplained. Chad Lewis and Terry Fisk of Eau Claire, along with Noah Voss and Kevin Nelson of Sun Prairie, are part of a team of investigators that respond to reports of unexplained phenomenon.

"For the last 13 years I've been traveling the globe in search of the paranormal, everything from vampires and UFOs to crop circles, mysterious creatures, haunted places, curses, and the like," said Lewis, addressing 250-odd audience members at the Unexplained Conference Saturday.

"And throughout these 13, 14 years I've often discovered that some of the strangest things were right in my own backyard, right in Wisconsin."

The podium light cast shadows on Lewis' face, darkening his eye sockets like a campfire ghost storyteller. A screen behind him flashed sketched and digitally-created images of mysterious creatures ranging from the familiar Bigfoot character with a Planet of the Apes beard to aliens with almond eyes to rock-throwing gnomes and hovering spheres of light not unlike phosphorescent billiard balls.

Despite having traveled the world and investigated hundreds of stories, Lewis said he has never had a paranormal experience.

"Never," he said. "In 14 years I've been to some of the most paranormal places and I have yet to have an experience in (the paranormal). I think maybe that's what keeps me moving too, going, looking for maybe that experience."

Lewis first became interested in the paranormal in high school when he heard about UFO sightings in Elmwood, Wis. Traveling to the town and speaking with residents fueled his interest in exploring these unexplained occurrences. In college and later graduate school, Lewis studied psychology, researching whether religiosity, income, gender, or education factor into why some people believe in aspects of the paranormal and others don't.

"And I started presenting that research and people would come up and say, 'I know this isn't really what you are doing, but I think my home may be haunted, could you help me out?' Or, 'I saw something in the sky last night,' " Lewis said.

"Tonight I'll probably hear 50 stories from people and I love it. For a lot of these people they may not have told these stories for 20, 30 years because they didn't think anybody would believe them. And a lot of them don't want any further research done, they just kind of want to tell you to make sure that others are experiencing the same thing."

For all the interest in the unexplained, getting funding for paranormal research is difficult, the investigators said.

Lewis , along with co-host Fisk, hosts "The Unexplained" radio and television series and also authored "The Wisconsin Road Guide to Haunted Locations." Often compared to Fox Mulder of "The X-Files," the investigators spend a fair amount of time keeping vigil in basements, scanning fields and roadsides for clues and presenting their research at various conferences and venues. The two are also working on a second paranormal road guide with additional Wisconsin haunted locations.

Not just any site can make the haunted list. In researching the book Lewis said they look for sites with a history of paranormal activity including multiple eyewitness accounts. Then, the investigators travel to check out the validity of the site, often testing the area with various types of equipment.

"Most of the ghost hunting, that's what it's called in generic terms anyway, gear is mainly designed to rule out natural explanations. Like an EMF meter, an electromagnetic field, is designed to test whether there is faulty wiring in a wall, basically, they are to rule out things that are there from a natural phenomenon," said Voss.

In 2001 Voss started getghostgear.com, a business that sells ghost hunting equipment including thermal imaging cameras, air ion counters and baby powder for dusting entryways.

Despite all the fancy gear, tangible results are hard to come by in the ghost hunting world. Most of the mysterious images the investigators presented in the slideshow were crafted; they are scaly aliens sketched based on people's memories or photos of an empty field where UFO sightings were reported. But the stories the audience shared were not so easily dismissed.

One man reported seeing his grandmother, whom he'd always known in a wheelchair, standing and healthy by his bed the morning after her death. He said she faded away when he said her name. Others reported seeing visions of loved ones and later learning that they'd died around the time the vision appeared.

The beliefs, at least, are real.

"Part of the work you do is almost a social worker. You just listen to the stories and again, most of the people, 99 percent of the people I've ever spoken with out of the thousands, are normal, rational, logical, intelligent people, they just had something weird happen to them," said Lewis.

"So I think a lot of it is that they just want to have you tell them that they are not alone. For years people wouldn't talk about it because they thought they were the only ones."