sentence: Many haunted houses are believed to contain ghosts.
sentences_before: A 'haunted house' is a house where supernatural events are believed to take place.
sentences_after: They can also contain the spirits of dead people. The rumour that a house is haunted often starts after something violent or tragic happens in the house, such as a murder or suicide. Haunted houses are common in gothic fiction, and are generally seen as old castles or creaky, old, abandoned houses. One scientific explanation of haunted houses is that poisonous gasses such as carbon monoxide from defective gas-burning appliances are what causes the hallucinations that people experience. Another possible cause is infrasound.
concept_name: haunted house
headings: Haunted house
categories: Occult