The human body uses electrical pulses to carry signals from one part of your body to the next. In order for your finger to click the mouse button, the brain must send a signal down to the finger to drive the muscle for clicking. These energy pulses are traveling through the body at an alarming rate and can be detected by an EMF detector if it is sensative enough. Energy for the most part, stays withing its own electrical system (the body) but some does escape. It is believed that once the body dies, this energy is released (the soul) and since the body is no longer dampening the energy, the radiation would be much stronger and give EMF detectors the ability to detect its existance.

EMF detectors need to be used with care and are a complimentary device and not something to base your entire investigation on. EMF spikes can be caused by paranormal activity, but can also be caused by natural phenomenons or even man made frequencies that just happen to be bounced your way. For instance... you are investigating in an old warehouse in the middle of a large town or small city in the middle of the night, the warehouse has no electricity and the only device on and running is your EMF detector and a flashlight. You are perusing the scene whenn all of a sudden it spikes to 7 and hangs there for 5 seconds then fades back to 0. Obviuosly this has to be a paranormal event, there is no electricity on in the place and thes only devices going is your EMF detector and a flashlight. Unfortunately this can also be a man made phenomenon and the source would be difficult to track down. Activity such as this can be caused by a large object like a mac truck sitting at a redlight which is bouncing radio waves in your direction off the side of the trailer for the 5 seconds while its sitting at a stop sign 2 blocks away.