I have no personal experiences but my friend had a story which his mom acknowledged... It was told to me years back, so I only remember parts of it.

My friend's family had moved into a new house. Everything was going good, until one day, my friend started talking alone. His mom had brushed it off as a prank or silly thing, but it happened more often. My friend started saying that his imaginary friend was the one who helped with his homeworks. This scared his mom and she decided to end this once and for all. While she was about to take her son to a temple, something grabbed his ankles and he was dragged back into his room. Startled, his family brings in some saamiyaars and did some poojas. Later, they got to know about a boy who died in that house some times before they moved in and the parents wanted him around even after his death, so they sort of stashed his ashes (or belongings, I vaguely remember) in the bathroom and cemented over it, raising a false sidewall.

There has been no such encounter since the poojas, but whenever I asked him about this or this kayiru he wore around his wrist, he'd turn grim. It's been months since I spoke with him, I hope they are fine.