Typically, a ghost "hunting party" will involve 4-8 individuals who work as a team to collect evidence of paranormal activity. Ghost hunters usually record data in a scientific manner, making observation using electronic equipment of various types, such as; EMF Meters, digital thermometers, infrared, thermographic, and night vision cameras, Hand held video cameras, digital audio recorders, and computers. Organized teams of ghost hunters are also called paranormal investigation teams.
Critics of ghost hunting say there is a total lack of scientifically testable and verifiable evidence in favor of the existence of ghosts, despite centuries of interest in the subject.
Origins
Pliny the Younger recorded what has been regarded as the first story of a ghost hunt in 100 AD. The story was already a century old when Pliny told it, and concerns a haunted house in ancient Athens being investigated by a philosopher named Athenodoros Cananites.
The Ghost Club, founded in London in 1862, is believed to be the oldest paranormal research
organization in the world. Famous members of the club have included Charles Dickens, Sir William Crookes, Sir William Fletcher Barrett and Harry Price.
In the mid 1880's, William James, philosopher and founder of the American Psychological Association and brother of Henry James suggested applying scientific method to paranormal questions such as the existence of ghosts or spirits. He found allies in England such as Alfred Russel Wallace, Cambridge philosopher Henry Sidgwick and his wife, Eleanor, Edmund Gurney, and others to form the core of the Society for Psychical Research to collect evidence concerning apparitions, haunted houses, and similar phenomena. The investigators gathered case studies, attended séances, designed tests of claimants' veracity, and ran what came to be known as the ''Census of Hallucinations'', which counted apparitions of persons who were said to have made spectral appearances on the day they died
Similar investigation into hauntings was undertaken by Harry Price through London's National Laboratory of Psychical Research during the 1920s, and later in the 1950s and 60s by American independent researchers such as Hans Holzer and Ed and Lorraine Warren. Other paranormal and parapsychology investigators like Loyd Auerbach, Christopher Chacon and William Roll were each independently conducting field and laboratory investigations in the 1970s and 80s, long before reality TV cast a spotlight onto this subject matter.
Ghost hunting among part-time hobbyists began to be popular in the late 1970s with the founding of the Chicago area Ghost Tracker’s Club, which became the Ghost Research Society (GRS) in 1981. The popularity of the Ghostbusters movie of 1984 may have boosted the proliferation of such "ghost clubs". In the last decade, the term "paranormal investigation" has increasingly been adopted by hobbyist and professional groups who do not investigate any other aspects of the paranormal such as Extra-sensory perception and Psychokinesis, but whose sole purpose is ghost hunting.
Growth
Easy access to information on the world wide web, movies, particularly Ghost Busters, and TV shows, particularly Ghost Hunters are thought to be partly responsible for the current boom in ghost hunting. One popular website for ghost hunting enthusiasts lists over 300 of these organizations throughout the United States and the United Kingdom. There are now hundreds of Internet message boards and web sites dedicated to the pursuit. Many of the sites declare themselves free of Ouija boards, which are frowned upon as unscientific among some paranormal enthusiasts. Along with ghost tracking tips, the sites discuss everything from high-tech equipment to analysis of investigations. Many feature ghost photos and videos, often appearing as blurry mist or blobs of light, called “orbs” by insiders. Similarly, audio recordings are referred to as "EVPs," or electronic voice phenomena, sometimes sounding like garbles and warbles amid background noise.
Scores of small businesses selling ghost-hunting equipment, ghost investigation services, and even ghost counselling, are booming outside of their prime season, Halloween. Several companies recently introduced new devices billed as ghost detectors, along with the traditional electromagnetic field detectors, white noise generators, and infrared motion sensors. The paranormal boom is such that some small ghost-hunting related businesses are enjoying increased profits through podcast and web site advertising, books, DVDs, videos, and other commercial enterprises.
Among ghost hunters, some are also devotees of urban exploration, a growing hobby where enthusiasts venture into abandoned structures such as hospitals, asylums, and sanatoriums.
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While interest in the paranormal heats up, so does the competition between ghost hunting organizations. As many groups scramble for publicity, rivalry and feuds are common. Commercially-active groups such as TAPS (The Atlantic Paranormal Society) and IGHS (International Ghost Hunters Society) often attempt to discredit the others legitimacy
Ghost hunting equipment and methods
Ghost hunters use a variety of tools and techniques to investigate alleged paranormal activity. While there is no universal acceptance among ghost hunters of the following methodologies, a number of these are commonly utilized by ghost hunting groups.
Non-objective "equipment"