"I think the Yule tree is haunted," Harry complained.
"What makes you think that?" Severus asked.
"Everything is re-arranged every morning. And the tree is moved slightly."
"It would be a poltergeist, not a ghost, then. You know ghosts cannot make something move."
"Has anything been damaged?"
"No. That's part of the mystery. I don't know how long it's been going on, I only noticed because the tree itself had been moved."
"When did you first notice?"
"Three days ago."
"I would assume it is neither dangerous nor important."
"Since you put it that way... I guess it's not."