A childhood belief about people

My grandmother once showed me a photo of a little girl in a photo album. She told me that this girl used to live next door, and that she was playing in her room one day. Her parents, who were downstairs, heard a thump from her room, and when they got there, she was dead on the floor. She had been playing with a plug socket, and had been electrocuted. This gave me the worst nightmares of my childhood.
I later found out that the girl in the photo was my Aunt, aged about 4. I have no idea why Nana told me this, it was completely unprovoked, and we hadn't been discussing anything to do with electricity etc when she told me...we had been having a great time looking at old pictures!!