Magical creatures in Harry Potter harbor an attraction to imagery morbid and melancholy. Ghosts are very sensitive about their condition: when the Ministry initially classified them as sentient creatures with full legal rights, they claimed that the term was insensitive and received a separate "Spirit Division", apparently to control the activities and haunting locations of troublesome ghosts (as when Myrtle was forced to haunt the place of her death (Hogwarts) after she had disrupted the wedding of the brother of Olive Hornby, a girl who had teased her at school). Named Ghost characters: Peeves, the Hogwarts poltergeist, is not considered a ghost, but an "indestructible
Poltergeist and cognitive dynamics of percipients' interpretation of ambiguous stimuli". Psychologist Donovan Rawcliffe has written that almost all poltergeist cases that have been investigated turned out to be based on trickery, whilst the rest are attributable to psychological factors such as hallucinations. Attempts have also been made to scientifically explain poltergeist disturbances that have not been traced to fraud or psychological factors. Skeptic and magician Milbourne Christopher found that some cases of poltergeist activity can be attributed to unusual air currents, such as a 1957 case on Cape Cod where downdrafts from an uncovered chimney became strong enough to blow a