"Similar, I think, but not quite. A wraith, in fact, which sounds an awful lot like what you're describing than something I'd consider a ghost. Not necessarily violent until disturbed, but incredibly dangerous to mess with if you don't know any of that." With a light gesture at Hanna, more to the description he gave.

"We found one, a woman that had lost her baby, and had ended up kidnapping a second child to replace it, but- obviously that wasn't proving a solution. John and I helped release her from her torment, by- trapping her in an item of sentimental value, and making a deal with her for her freedom."