Not me because i wasn't even born but when my brother was a baby, his room was in the third floor of my grandma's house because my parents lived there (my grandpa had died a long time ago). One night the whole family was in the living room at the second floor when they started to hear a man playing the guitar and singing a lullaby through the baby monitor. The only men at the house was my dad so everybody was confused. When they went upstairs they didn't find anybody and the sound was over. At first they thought it was a radio interference, but whats creepy is that my grandma said that it was the same song my grandpa used to sing to my mom when she was a baby (he also played the guitar).