A study concluded that women may report paranormal experiences when they are under stress. Possession and extrasensory perception were found to be associated with traumatic stress.
Perhaps ghosts are simply extremely low sound frequencies. In particular, infrasounds, which are sounds below the audible range of humans.
What is a scary, spooky location without some mold? Certain varieties of mold can, in fact, induce hallucinations and impair balance and coordination.
People who have experienced the loss of loved ones have claimed being visited by them. The apparitional visits may be a coping technique employed by the bereaved brain.
Paranormal activity may be indicated by cold areas in a property. A fast temperature shift doesn't indicate a ghost, though.
The Journal of Ophthalmology described a couple's paranormal experiences in the 1920s. A CO leak in the furnace caused their hallucinations.
Exploding head syndrome occurs when a loud noise is experienced, typically when falling asleep or waking up. It sounds like a phantom explosion.
Sleep paralysis causes paranormal experiences. This happens when you're dreaming yet can't move. It's often perplexing and scary.
A scientific explanation can be found for those small balls of light that so many people believe to be the ghosts of the dead.
As with any other belief system, believing in ghosts helps us cope with our own death and makes sense of our place in the world.