As far as ghostly activity goes, I've never actually seen anything, or felt anything that I know of, but there's no doubt at all that strange things have happened around me and my family, and it seems to move with us wherever we go.
I had never in my life experienced any kind of paranormal phenomenon, other than occasional odd feelings and noises that could be explained away, until 2003. That's the year my father passed away rather suddenly from a stomach aneurysm. We had a very rocky past, including my parents divorcing when I was 4, but we had reconciled and became very good friends when I became an adult.
A few weeks after he died I received an unusual phone call. My wife checked the messages on our phone and told me there was an odd message and wanted me to check it out. What I heard still gives me chills to this day. It was a call from a cell phone (I think), and the call came from a bar of some kind, where there was a musician playing the song "Cat's In The Cradle". Now, for years there had been a private joke between my father and I that when he would call and I could not get to the phone, he would leave me a message and reference that song. Sometimes he'd quote from it or hum a line or two... it was a joking way for him to put a guilt trip on me for not being there when he called. The message I got ran for several minutes, until it just cut off. It freaked me out so bad I burst into tears on the spot, and my wife had absolutely no idea what was going on... no one else, not her, not my mother, nobody had any idea of that joke my father and I shared.
After that, we began hearing noises in the apartment... movement and things that were decidedly different from the stuff we were used to after living there for 2 years. The sounds were closer, sometimes right in front of or behind us, and there was a feeling that someone was there with my wife and I... always us... our children never experienced anything, to my knowledge. It came to a head one day when it was storming out and my wife came home with an armload of groceries... as she approached the front door it opened for her. She thought I or one of the kids did it, but we were all upstairs. Not long after that we got a house, but my neighbors in the apartment told me when I stopped by to get the last boxes (several days after we began sleeping in the house) that they had heard noises in the apartment. My neighbor got concerned and walked around outside, shining the light in the windows (the blinds were gone). He saw nothing, and the doors were still locked. He said it sounded like pacing, and repetitive walking up and down the stairs.
Our house was pretty new, only 5 years old, and the guy who owned it before us rarely stayed there. He worked all over the country and was barely at home. For the first few months we experienced nothing in the house, then, all the sudden, alot of activity began to happen. There would be areas of the house that smelled of cigarette smoke (my father smoked, as did my mother in law, who died a few weeks after we moved into the house) even though we don't smoke and don't allow it in the house. What's more, the smoky areas would change, eliminating the possibility it was merely a piece of clothing or something stationary. When my wife became pregnant with our third child, the lights in the office would flicker. We turned it off and plugged in a floor lamp... it too began to flicker. We attributed it to an electrical problem and left the light off. After my son was born, he spent three months in the hospital (he has cystic fibrosis and had lots of complications). Sometime after he came home, the light in the office was turned on again (I don't know who did it, but it was likely one of my older kids) and to my knowledge it never blinked again... not one time.
I'll wrap up with this. Whatever it is has taken a fondness to my young son's toys. Just last week we all (me, my wife, my 8 year old daughter, 5 year old son, and the baby) were sitting in the living room playing with Charlie (the baby) when one of his toys on the other side of the room started playing music by itself. You press a button and it plays once, but this time it played by itself THREE TIMES, when nobody was near it. It has since not done any of that and is working normally; the batteries still seem fresh, and it doesn't appear to have a short. Later that night, a different toy also played by itself, this time in the bedroom, also with everyone present.
Three nights ago, another incident occurred. The front door, which was locked, opened for my wife as she approached. Just like the time in 2003, she was carrying groceries. That's the first time it had happened in our new house. She informed me last night of an incident I had forgotten. In 1998, when we lived in an apartment in DeRidder, Louisiana, the exact same thing happened to my wife... she was carrying groceries, and the door opened as she approached.
Now, I realize each of these things can be explained away as individual acts of chance, but it is very odd to me that the same types of things (particularly the doors) have happened over and over, in different locations, always when doing the same activity. I really am at a loss to explain what it is, if anything, that is causing these things. The acts don't seem to be tied to a particular person or place, and it is really freaking me out.