'Mould may be the reason behind ghost sightings'
Scientists think ghost sightings could be the result of mould.
According to researchers from Clarkson University in New York, the toxic effects of some types of mould cause hallucinations.
Civil and environmental engineer Shane Rogers said:
"Hauntings are often reported in older-built structures that may also suffer poor air quality.
"Similarly, some people have reported depression, anxiety and other effects from exposure to biological pollutants in indoor air."
Spores can cause significant mental or neurological symptoms, which can in turn lead to hallucinations, some of which may have caused people to think they're seeing ghosts.