Not so original concept, sorry
"The Reaper's Image" by Stephen King.
Read the story, give credit where credit is due...
You're absolutely right. I forgot about that short story in Skeleton Crew until you said it. He even stole the crack in the mirror idea lol!! Good call, I was tired of everyone comparing this to Mirror, when it really was nothing like Mirrors. This was almost exactly "The Reaper's Image"!!