A haunted house, spook house or ghost house in ghostlore is a house or other building often perceived as being inhabited by disembodied spirits of the deceased who may have been former residents or were otherwise connected with the property. Parapsychologists often attribute haunting to the spirits of the dead who have suffered from violent or tragic events in the building's past such as murder, accidental death, or suicide. In a majority of cases, upon scientific investigation, alternative causes to supernatural phenomenon are found to be at fault, such as hoaxes, environmental effects, hallucinations or confirmation biases. Common symptoms of hauntings, like cold spots and creaking or knocking sounds, can be found in most homes regardless of suspected paranormal presences. People are more likely to experience a haunting when they are about to fall asleep when waking if they are intoxicated or sleep-deprived. Carbon monoxide poisoning has been cited as a cause of suspected hauntings. If there is an expectation of a preternatural encounter, it is more likely that one will be perceived or reported. History According to Owen Davies, a paranormal historian, hauntings in the British Isles were usually attributed to fairies, but today hauntings are usually associated with ghostly or supernatural encounters. In other cultures around the world, various spirits are said to haunt vacant homes and locations. In Middle Eastern countries, for example, jinn are said to haunt such areas. Historically, since most people died in their homes, whether they were mansions or hovels, these homes became natural places for ghosts to haunt, with bedrooms being the most common rooms to be haunted. Many houses gained a reputation for being haunted after they were empty or derelict. Davies explains that "if people were to fail to occupy a human space, then external forces would move in." Cultural attitudes to haunted houses Haunting is one of the most common paranormal beliefs around the world, according to Benjamin Radford in his book Investigating Ghosts: The Scientific Search for Spirits. He says that almost every town and city has at least one "haunted" place; and that, despite over 100 years of investigation, there has not been a "single verifiable fact about ghosts having been established." In the first century A.D., the great Roman author and statesman Pliny the Younger recorded one of the first notable ghost stories in his letters, which became famous for their vivid account of life during