I've managed to keep from "debunking" several ghost/angel photos shown to me by inlaws out of courtesy.... but..
During some holiday visit I was handed a picture and the mother of the boy in the photo insisted that he was being watched over by a spirit/ghost/angel/etc. I nodded and went to file it in the back of the stack, but she stopped me. See? She says, indicating the picture with stabs of her finger. "It must be [relative who died, can't remember relation] watching over him".
I swear I held out... fought so hard... "Really? Was this taken at your house? (yes) by you? (yes) and were you HOLDING A CIGARETTE in your hand, like you always are. As in right now in my face? (huh?)"
Another family member glances over and chuckles, "Sure looks like a puff of cigarette smoke hit by a flash to me" he says helpfully.
Yeah, she doesn't show that picture... or talk to me as much anymore.
Guess I'm a jerk.