Little Boy Crying

Back in 1987, my sister and her husband used to live in an apartment. Her husband's mother lived upstairs and this was in a house but both apartments were separate from each other. One day, when my sister was home alone, she went down to the basement during the day to do some laundry and she heard a little boy crying in the dark. My sister was nervous of turning on the light. So, she asked him "Little boy, why are you crying?" He responded "Because I don't like the dark!". She told him she would get a night light for him. When she returned and plugged the night light into the outlet... he must of vanished and she could no longer hear him. My sister found out later that years ago a family lived there once and their little boy died of a disease in a hospital not to far away.