I grew up in a home in Long Island, NY that my parents purchased from two older women that lived there for many years. I was about 5 years old at the time, and like so many young children, I would get scared and run through the house to my parents bedroom in the middle of the night to sleep with my parents. One night, just as I was about to enter my parents bedroom, an apparition of a little girl appeared in the doorway of the spare room at the end of the hallway several feet away. The apparition was a faceless blueish-white vapor in the form of a little girl, maybe 4 or 5 years old and wearing a "Shirley Temple" style of short dress common in the 1930's and 1940's. She floated to the threshold of the spare room and stopped as if to see who was coming down the hallway. Mortified, I dove into my parents bed and under the covers I went. Of course, when I told my mother about my experience the next day, she thought I just had a wild imagination and dismissed it.
Many years later, when my mother passed away, I was visiting with my father. I was then in my mid twenties. There were some strange occurrences in the house the night she passed away (another story), and we got into a discussion about ghosts and the afterlife. My father was a total non-believer. I told him of my experience of seeing the little girl apparition as a child and his expression changed and he turned white as a sheet. He told me that the old ladies he bought the house from had a little girl that passed away in the house due to polio. Because the house was well priced and was a great deal and he was a total skeptic about hauntings, he purchased the house and never told my mother about the death in the house. He was shocked to learn of my experience with seeing the little girl. That experience has been with me all of my life and definitely made a believer out of me.