Paranormal researchers have for several decades researched the connection between electromagnetic fields (EMF) and psi-energy and paranormal phenomena.  The widely accepted theory is that erratic EMF's are present when paranormal activity occurs.  It is believed that ghosts give off a pulsating EMF field which is registered as a sudden spike on the EMF meter.  Man-made EMF's are almost always steady.  Various electronic appliances emit various levels of EMF's.  Humans emit a low field of 0.2 milliGuass (mG).  So, EMF's are always around us at low levels, and sometimes at high levels.  When the K-II EMF meter is on, the first led light (green) is always on.  Paranormal activity is most commonly registered between 2 to 6 mG, hence sometimes spiking up to the second light and sometimes up to the third light.

When you are at a site and feel the presence of an entity, then simply activate the meter through pushing the button.  The meter always spikes once when you turn it on to show you that all lights are working properly.  Keep the button pressed down to keep the meter turned on.  When you want to keep the meter on without having to press the button down, then slip a small object such as a paper clip or a coin (such as a penny or dime) into the slit by the button.  This will keep the meter constantly turned on.

When the meter starts to suddenly spike, take photos.  Paranormal entities often produce light phenomena in photographs.  Also, apply all of your senses.  Ghosts are believed to sometimes give off various scents, sounds, and sometimes people are touched by them or a sudden drop in temperature is registered in the area when a ghost is present.  And, of course, sometimes people see the ghost, even if this is the most uncommon way of experiencing them.  On occasion, people claim to have been able to taste the smell of the ghost.  People that are sensitive also experience different types of feelings such as sadness or anger at sites.  It is quite common that someone who experiences a haunting feels like time is standing still and is in awe at the unusual aspects experienced during the event of the phenomena.  Many people have reported an elated feeling of peace and tranquility.