EMF stands for an Electromagnetic Field. Any item that utilizes electricity, as well as natural geological sources, give off EMFs. This field is comprised of a stationary electric charge and a flowing magnetic current, measured in the number of volts per meter. The most common measurements used are Gauss (G) and milliGauss (mG). For instance, the average microwave EMF reading at close range is between 40.0 mG to 100.0 mG, at a distance of just 5 feet, the readings drop to 5mG or less.
So what's a "normal" EMF level in your average home? Depending on which sources you consult, they range from 0.0 mG to 0.3 mG, with anything above a 0.7 mG being considered unhealthy, to anything above 2.0 mG being considered too high and unhealthy.
Some people are more sensitive to high EMF levels. For them, they can become ill if exposed to too much. Some common symptoms are upset stomach, headaches, and even visual/auditory hallucinations.
There's a large debate in the paranormal field as to wether or not high EMFs cause people to believe they're seeing/hearing spirits as a result of hallucinations, or do areas with high EMF levels attract spirits and/or provide more energy to manifest at that location. Perhaps it's a combination of the two?
You're probably familiar with the scientific theory that states that energy cannot be created nor destroyed. Energy is a vital part of our bodies abilities to run properly. The belief is that once we die, our spirits are made up of the same energy we had while alive. Thus, while investigating, paranormal teams look for unexplainable spikes in EMF that have no natural causes. These "spikes" could indicate the presence of a spirit.
However, in paranormal research an unexplainable EMF spike alone holds very minimal proof of paranormal activity. In connection with audio, video, or photographic evidence, it helps to support that piece of evidence further. The spikes can also help us discover patterns, and even allow us to communicate in real time.
All in all, the EMF meters are a must for anyone interested in investigating the paranormal. Not only do they allow you to track & communicate with spirits, they also can help you to find alternative natural causes for activity.
Websites for additional EMF scientific research:
Founder & Lead Investigator
Mystique Paranormal Research Society (MPRS)