Well, I sure seem to have garned more first-hand accounts of ghostly experiences that I had expected when I started this thread. As I mentioned earlier, I have never had any kind of supernatural encounters, which suits me just fine, but I will narrate a few involving people I have known.
One day, about 80 years ago, my grandmother heard someone crying next door to her house. She thought a little neighbor boy had gotten trapped in our neighbor's garage and dispatched my uncle, then about 13, to set him free. Suddenly, she saw our neighbor walking up his driveway, holding his wife's dead body and weeping. She shrieked for my uncle to return. It seems our neighbor's wife had hanged herself in the garage. To the other side of the hanged woman's house lived an attorney named Whitney Smith with his wife and daughter. One night, a few weeks after the suicide, Mrs. Whitney Smith looked out her kitchen door and saw the dead woman standing where she had hanged herself with sort of a glow behind her. Understandably, Mrs. Whitney Smith began screaming, and the apparition vanished. Was this some sort of hysterical autosuggestion? Possibly...HOWEVER, I knew Mrs. Whitney Smith very well (she died when I was in my 30s), and a more hard-nosed, tough-minded, level-headed person of either sex you would be hard pressed to find. I could hardly imagine anyone less likely to be rendered hysterical by a figment of the imagination.
Another eerie story involves our Great Dane, Honey. For about 25 years my family employed an African-American woman named Sarah to do cleaning and laundry. The dog, generally a placid, docile beast, always reacted strongly to Sarah--whether this was the result of an instinctive aversion to people of color that some dogs display or the fact that Sarah had a sort of bustling, nervous manner to her, I can't say. Sarah lived just west of downtown Los Angeles on Bixel Street, about three miles east of our house. One night, Honey appeared at her door. She was very surprised that the dog could have found her way through three miles of urban L.A. to her door, but she let her in. The dog went into a corner a lay down and remained there until Sarah went to bed. When Sarah awoke in the morning, the dog was gone. When she arrived at our house that morning, she started to tell my mother this strange story and wondered if the dog could have found her way back home. My mother cut her short, saying, "Oh, Honey died last night at the veterinarian's."
My second wife told me that her grandmother had moved into a haunted farmhouse in Wisconsin. There were a number of strange phenomena, the most memorable of which was the repeated sound of an infant crying. Finally, the old lady had enough and performed an impromptu exorcism by pounding on the floor with her broom handle and shouting, "Clear out or pay rent!" Evidently it worked, as all ghostly activity henceforth ceased. If the old lady was anything like as formidable and mean as her granddaughter, she would have been terrifying enough to spook the spookiest of spooks!
My second wife herself experienced some strange, ghostly phenomena when she was staying in Hawaii near where human sacrifices had allegedly been performed back into old days of the pagan kingdom, the strangest of which was seeing a ghostly column of men in ancient Hawaiian attire marching across the property. Supernatural phenomena seem to be exceptionally abundant in the Hawaiian Islands, I get the impression.
In the last years of their lives, my mother and uncle were good friends with two gay men who lived in an old house not far away. The children of a previous owner didn't want to sleep in their bedroom because "a man came out and frightened them." The two gay men never experienced anything untoward, but a friend of theirs was so freaked by something he experienced there he refused to go upstairs in their house ever again. One day my mother dropped by to pay them an impromptu visit. Although she saw somebody moving about in house, no-one answered the door, and the boys confirmed they weren't at home at the time. She was convinced she had seen the ghost.
A noted figure in the gun culture told me that when he was living in one house in Orange County he and his wife experienced a lot of supernatural phenomena. The young daughter of the previous owners had disappeared during the hippie era, presumably the victim of foul play, and my friend surmised that it might be the spirit of the dead girl trying to find her way home.
Anyway, these are but some of the ghost stories involving people I've known personally.