Appeared in Tor.com
11-year-old Jack doesn't just see ghosts, they attach themselves to him. When his teacher, Mrs. Jernigan, "dies of meanness" in class, she attaches to him, which isn't too cool until she slaughters a dream monster that leaves real bruises on his arms. She gets nicer, though, because Jack gives her silent treatment whenever she insults his intelligence for something he did. Roger, a ghost who'd been murdered by the 7-11, uses Roger to make sure his mother is still taken care of.
Jack loses one ghost and gains another. Mrs. Jernigan introduces the new ghost and promises to teach him her skills.
Feels like the opening to a longer story, or maybe a series of stories.