About 90 people tiptoed around night-vision cameras atop tiny silver tripods and dodged remote sensors connected to a computerized surveillance system. They waited for the Lincoln ghost train, which some people believe passes through the western Ohio city of Urbana on the anniversary of the 1865 trip that carried the president's body to Springfield, Ill., for burial.
Ghost-hunting groups around the country are swelling with members, their popularity fueled by television shows, the Internet and the increasing availability of high-tech equipment.
"Academics pooh-pooh all of this usually," said Julieanne Phillips, an assistant professor at Urbana University. Phillips invited the ghost hunters and organized the vigil that also included about 80 students and residents. "I'm hoping for some vindication that there might be some type of paranormal activity surrounding this."
On this night, there wasn't.
"Ghost reality shows have really opened the door for people to get involved themselves," said James Willis, founder of The Ghosts of Ohio, the group watching the tracks for the paranormal train.
The TV airwaves are populated with shows such as "Ghost Whisperer," "Medium," "Paranormal State" and "Ghost Hunters."
Viewership of "Ghost Hunters," a reality show on the SciFi Channel that chronicles investigations by the Atlantic Paranormal Society, has doubled since it debuted in 2004, growing from 1.3 million viewers to 2.6 million.
The Rhode Island-based society currently has about 80 affiliates in 44 states, twice the number of affiliates it had two years ago. And there are about 800 individual members within those affiliates, up from 300 three years ago.
"Thank God for the "Ghost Hunters' on SciFi," said Patti Starr, founder of the Lexington, Ky.-based Ghost Chasers International. "Through that show, I think people see we are really serious about what we do and they've raised the bar."
Even the U.S. Air Force has gone along, inviting "Ghost Hunters" to investigate reports of unusual occurrences at Wright-Patterson Air Force Base near Dayton, Ohio. The episode showed a flashlight turning on by itself and unexplained knocks and door closings.
Local groups also are feeling the surge of interest in ghost hunting.
Susan Bove, founder and co-director of South Jersey Paranormal Research, said, "For the first time in our history, this year we actually put a hold on taking new members, because we had so many people.
Bove, of Glendora, said the research group maintains about 35 members on average, but has reached as many as 60 members. While she is excited about the increase in interest and thinks a lot of new members do great work, she has noticed some negative effects of recent popularity in paranormal research.
"It's great that people want to partake, but I wish people would get the appropriate training," said Bove. "What we're noticing more of is an increase in people having an inexperienced group come in and the group either doesn't do anything for them or makes it worse. We've also had people call who think it's just fun to have a ghost group out, but don't have a real problem."
A Midwest Haunting, based in Macomb, Ill., offers October tours of buildings, cemeteries and other sites it has investigated and believes to be haunted. The number of people taking the tours has tripled, jumping from about 600 in 2006 to 1,800 last year.
Forty of the 60 people who attended a recent dinner in Erie, Pa., that featured the Paranormal Study and Research Group asked if they could join the group or tag along on ghost hunts. A year earlier, only two or three asked to be involved after a similar event.
"We're actually grateful for ("Ghost Hunters') because, instead of being a bunch of freaks, we're like the cool people on TV," founder Pat Jones said. "People used to look at us like we were absolutely insane and now they want to come along with us. It's almost like every day is Halloween."
More than 500 people have registered to post and read messages and articles on the Idaho Spirit Seekers' Web site since the message board went up in November. "That really shows the interest that people do have and that it's becoming more acceptable to talk about," said executive director Marie Cuff.
Thirty-four percent of Americans say they believe in ghosts, according to a survey conducted in October by the Associated Press and Ipsos.
Joe Nickell, senior research fellow with the Amherst, N.Y.-based Committee for Skeptical Inquiry, said he has investigated dozens of reported hauntings since 1969 and has turned up no evidence of ghosts.
Equipment being used to try to detect ghosts is not designed for that, Nickell said. Ghost hunters often arm themselves with electromagnetic detectors, thermometers that can identify cold spots and wireless microphones that eliminate background noise.
Orbs of light that show up on photos, he said, are often tiny particles of dust or moisture close to the lens of the camera, "voices" picked up by tape recorders can be radio signals or noise from the recorder and electromagnetic detectors can be set off by faulty wiring or microwave towers.
"The least likely explanation for any given reading is it is a ghost," he said.
Jacqueline Foreman, 38, of Marlton, is the lead investigation analyst and field researcher for Orion Paranormal's Mid-Atlantic Region. She owns a lot of her own equipment and said people would be surprised what electronics work great in paranormal investigations.
"A digital tape recorder . . .," said Foreman, "excellent thing to have with an external microphone so that you can hear more noise. K2 meters are great and they're only about $40 to $60. They have lights that go from green to red and various colors in between. You can say two blinks for yes and one for no and I've literally had conversations."
Foreman also has seen more high-tech electronics used specifically for paranormal investigation. One she mentioned was Frank's Box, a type of electronic voice phenomena analysis that translates paranormal conversations in real time. It was invented by an engineer named Frank Sumption.
Foreman explained how EVPs are acquired. "You walk around and ask questions . . . but to the audible ear you don't hear anything so you go back, play the tape and actually hear answers to your questions. But with Frank's Box you hear answers the moment that they speak."
Willis' group, which has grown to 30 members since it was founded in 1999, includes both true believers and total skeptics.
"If you want to be taken seriously in this field, you have to acknowledge that some of the stuff out there is not real," he said. "They're looking for answers, one way or another."