He inclined his head at her words, and explained. “It's rude to call spirits willy nilly, especially out of the spaces they inhabit.” Spirits had feelings and sense much like their living counterparts, and like dealing with fey and other creatures, not being rude was often a key in handling them. “Being pulled out of a space they're attached to can end badly, if the spirit is unstable. Today, I wanted to get a measure of your haunt, as well.”
He'd seen the stain on the wall, had seen marks of attempts of it being painted over, but it hadn't taken. So the supernatural was the most obvious answer, unless the men who lived in the apartment were dirty in specifically that spot, which was more unlikely.