Piligian says he was inspired after reading a New York Times story about two Roto-Rooter plumbers who also offered house calls to fix paranormal disturbances.
"The same qualities they used to fix a leaky pipe they used in their work to debunk whether or not a place was haunted," Piligian says. "It was almost mechanical in nature, and not so much voodoo."
Jason Hawes is one of those plumbers and now the no-nonsense star of "Ghost Hunters." A gruff guy with a shaved head and goatee, he's also the co-founder of the Atlantic Paranormal Society. He's feted at paranormal conferences, speaks at corporate events and has written seven books on his ghost-hunting experiences.
"The fame is great, but the minute I'm done filming, it's all about my family," says Hawes. He and his wife met in junior high and have five children. "I'm still a little plumber from Rhode Island."
Hawes said the popularity of paranormal shows has added visibility to the field, but that some shows have damaged its credibility because they don't take a scientific approach to cases.
He won't name names, but he says some shows launch investigations assuming a place is haunted and allow cable production companies to handle evidence, which he says leaves room for fabrication.
"Ghost Hunters" won't allow the Syfy Channel to touch any evidence, and nothing on the show is fabricated, he says.
"A lot of our cases never air," Hawes says. "We go in believing that 80 percent of all claims can be disproved."
Hawes, Bagans and other paranormal stars may be famous, but there's one ghost-hunting duo that stands above all the rest: Lorraine and Ed Warren, the couple depicted in this year's Hollywood film, "The Conjuring."
The husband-and-wife team were investigating ghosts before it was hip. They founded The New England Society for Psychic Research in 1952 and investigated the notorious paranormal case that inspired the book and film "The Amityville Horror."
Ed Warren died in 2006, but Lorraine, who was portrayed by Oscar-nominated actress Vera Farmiga, discovered during a recent trip to the pharmacy that she's a celebrity herself.
"I had to pick up my prescription and the first thing they said was, 'Lorraine, you're a movie star!'"
When she left a premiere of "The Conjuring," she says she was surrounded by fans who wanted to know about her work.
Some asked if "The Conjuring" exaggerated all the spooky things she encountered.
"Maybe certain dramatic things, but not the important things," says Warren, at 86 a buoyant woman who calls strangers "honey" and seems tickled by her fame. "I'm very proud of it."
Warren is a devout Christian who says she became a paranormal investigator to bring people closer to God. "The Conjuring" is filled with chilling moments, but she doesn't consider herself brave.
"I'm brave in my faith," she says. "That's where my bravery comes from."
Their most terrifying cases
Thanks to TV shows and movies like "The Conjuring," paranormal investigators say they've never been busier.
Claudia Lee, director of Roswell Georgia Paranormal Investigations, says she has seen a "tremendous increase" in requests for help. When she and her investigators arrive at people's homes, their clients easily slip into the ghost-hunting jargon they've heard on TV -- talking about feeling "cold spots" or seeing "orbs" of floating lights.