The 20-year-old singer believes the family home she grew up in, in Texas, America, is haunted by a little girl, Emily, whom she befriended as an invisible playmate when she was younger.
She told BuzzFeed.com: "I go ghost hunting. My house in Texas is so ridiculously haunted. Not by a bad spirit, but a little girl. I think her name is Emily. I've had a medium come over and ghost hunters, and they both told me the same name, Emily.
"There were so many times that I saw her when I was growing up. I saw her in my closet one time. When I was three years old my mom caught me talking to something by myself.
"She asked, 'Who are you talking to?' and I said, 'My best friend Emily.' She's playful."
Demi - who has a sense for spooky goings on - has talked to a medium, someone who mediates communication between spirits of the dead and other human beings, and the pair discuss supernatural occurrences.
She added: "I think I have a really strong connection to the afterlife. My mom's friend is a medium, and we've talked about things... Stuff will just happen. When I walk into a room, I can tell if something has happened there or not, or if a hotel is haunted."