Do you believe?

Researchers seem to use many electronic devices to detect paranormal activity. There are thermal cameras, EMF readings, EVPs, and some use Geiger counters. Some believe that the readings are evidence of the activity. The activity we perceive as apparitions, noises, and things moving around. However, there have been others that go into a house to find out why a family is "hallucinating", then found certain readings, and concluded that the family was seeing ghosts due to the abnormal Electromagnetic fields in the house. So, what do you believe? Are the readings proof of the paranormal...Or does the abnormal fields cause us to see and hear things?