Last October, I got an email from a woman named Kate, claiming to be the new owner of my late grandpa’s Los Angeles home. The emailer said her young kids complained about a scary-looking ghost that appeared in the back bedroom, with fingers missing from its left hand. The kids were shaken, and she was wondering if I could help. Her email pleaded: “Any idea what this might be, by chance?” At first, I thought this was a scam: a phishing email themed to the Halloween season. But the details in her