Yeah, I'm pretty sure this is a joke. As I understamd it, the "real" Mrs. Pete won't even acknowledge her own identity when answering her own phone. Yeah, I'd say she's haunted.
I don't know if that's Helen Peterman's address or not. Maybe it is. If you have anything to say to her, go ahead and say it. Who knows, maybe it'll do some good.
Maybe it'll open a dialog that can resolve some conflict. Maybe it'll open dialog that will force her to confront a logical conundrum that will result in her head exploding all over her livingroom. Wouldn't that make for an interesting headline...
At the worst, your email will bounce. At best, well, who knows? You never know. Just do it.