Deffinately, there are two main stages of ‘ghosts’ the way I see it.
Residual - This is the spiritual energy we leave behind both in life and in spirit. Strong emotions and feelings and similar things like that. This is the kind of energy you might pick up on when you walk into a room or building and suddenly get a really friendly or happy feeling or indeed a feeling of foreboding or something like that, yet not really know why you feel that way.
Other energies that would fall into this catagory could be if the building burnt down at some point and was rebuilt. This will leave a residual engery of that event that some people may pick up on, particularly if there was a lose of life involve.
Some visual & Auditory energy can even be picked up on by those who are very spiritually aware (psychic if you prefer) such as soft sounds. I went to an old monastery and at one point could have sworn I heard chanting. Speaking of I had a picture of the place https://img.photobucket.com/albums/v284/cit1981/old.jpg
Active/Visitation - This is the one where most spiritual/ghost activity falls.
There’s two main parts here, visitation and grounded. A grounded spirit is someone who has not moved on and stays here, maybe they did something really bad and are affraid to move on, others may chose to stay here or are trying to look for someone or things like that.
Visitation is what it sounds like, they come back to visit places they loved, people just to be nosy, whatever. Those that believe in spirit guides being real entities not a dream thing, this is where your spirit guide[s] will fall, a visiting spirit.
It’s these last two that provide the ‘ghost’ things, from visual and auditory to physical contact.
What have I experienced? I think I may have mentioned these in another thread here.
I once had someone say my name while I was in my room and everyone was sleeping, the voice came from the foot of my bed. They said my full first name which no one in the family generally does. I went right under the covers on that one, I was only 7/8.
Another time I woke up around 7am and hear someone right next to me say very clearly “Shhh you’ll wake him!” I guess he was right.
One of the scariest experiences I have ever had though, was in primary school in my second year. The room was fine normally, but when I was alone it felt very negative. Like you didn’t want to be there and just to get out. Sometimes I would be in there during break alone catching up on work and the old wardrobe that was in the store room would start to rock and bang.
One Lunch time I was in there with my friend and it started to bang, it was the first time I’d known it to happen with anyone else in the room and he asked what it was. It was at that point a blue white light, similar to lightning shot across the blackboard. My friend left me alone at that point.
A few years after that, I found out that that particular room used to be a bedroom when the original building was a boarding school and the wardrobe was also from that era. Whether something bad happened back then or something I have no idea, but at the time it scared the heck outta me.