TYPES OF HAUNTINGS AND THEIR CLASSIFICATIONS
Paranormal Phenomena:
LVPI classifies all Phenomena into three categories, which have sub-categories relating to their nature:
Terrestrial Phenomena:Terrestrial Phenomena is clearly related to Phenomena that is based on the planet Earth. This would include but is not limited to Human Psychic Phenomena (i.e. clairvoyance, precognition, ESP), Crypto-zoology (i.e. Bigfoot, Lochness Monster), etc. 
Extraterrestrial Phenomena: The addition of Extra excludes all terrestrial phenomena but incorporates anything that is not naturally of this earth such as UFOs, Alien Life Forms, etc. 
Spiritual Phenomena:This classification of Paranormal Phenomena includes Ghosts, Angels, Demons, etc.Classifications of Spiritual Phenomena:LVPI uses the same five classifications very similar to that of most scientific organizations:
Intellectual: A human who has evolved after the point of death into an energy or spirit being that roams the earth. There are many theories on why a spirit based human would continue to stay on the earth and interact with physical beings. Fear of Judgment: Like the myth of the Flying Dutchman and Davie Jones, the “sinners” of the world would make deals with other worldly beings in order to escape damnation even for a short time. The theory is that a person who lived a less than “auspicious” life will rather than face “the white light at the end of the tunnel” will hide because of the believe that at the end of that white light is “fire and damnation“.
Not All Who Wander:In most cultures there is a poor soul who rather than trying to escape their fate are cursed to wander the underworld in a dark bleak oblivion while they contemplate their former life.
Last Messages:Some beings are believed to be passing on a last message to loved ones, solving the mystery of their death, or simply tying up loose ends.
This is where most haunting stories get their scary stories as older locations known to be haunted are usually from people who were bad people in life and continue to be bad people afterwards. And the good souls finish their business and then pass on into the otherworld.
Residual: The theory is that a psychic imprint can be left in an area. Using different types of stone, crystals, etc. some environments carry over emotions from individuals. This includes items, houses, places, etc. There are no spirits here just an energy imprinted into something that replays and event or emotion over and over again. 
Poltergeist Activity:This comes from the German word meaning noisy spirit, however, this is usually not a spirit. Almost always associated with a young female the Poltergeist Activity occurs during a time of mental anguish and emotional distress. The theory is that unbridled psychic powers from the young woman create things to move (a form of telekinesis). However due to the enormous amount of energy these young ladies are using it is seen like a lantern in a dark cave to the spirits of the dead who move closer to draw energy to manifest themselves. 
Portal/Vortex:This is a dimensional doorway where the veil between dimensions is weaker or completely open. Places where vortexes or portals are would be considered the Bermuda Triangle, Goldfield Hotel, the Oregon Mystery Spot, etc. At these places investigators might find spirits of the dead attempting to gain access to the afterlife, Energy Based Life Forms attempting to gain access to our world, etc. 
Energy Based Life Form (EBLF):This is what is also commonly referred to as inhuman, an intellectual spirit that is not and never was a human being. This includes malevolent beings such as demons, and benevolent beings such as angels. Regardless of spiritual beliefs one thing is certain and that is that these beings are an EBLF.
TYPE OF EQUIPMENT LVPI USES FOR INVESTIGATIONS
Here is a list of some of the equipment used during investigations.
1. Trifield meter.
2.Trifield broadband meter.
3.Trifield natural EM meter.
4. A. W. Sperry EMF Meter.
5.Sony 7.1 megapixel camera.
6. Koday 3.2 megapixel camera.
7. Bushnell Nighthawk digital night vision.
8. Fluke 561 hvacpro thermal scanner.
9.Night Owl NON 5 night vision monocular.
10.Night Owl NOCX5m night vision monocular.
11. Panasonic rr-qr80 digital voice recorder.
12.Radio shack dr-85 125 minute digital voice recorder.
13. Sony ICD-B7 digital voice recorder.
This is just a small listing of equipment used to hunt the paranormal.