I am trying to identify a horror story that I read about two years ago. I remember part of the story involving a man in a cabin with a horse being attacked by a demon that had been sealed in a well and covered with rocks with some type of glyphs or script on them. Presumably these rocks were enchanted to keep the demon trapped. This may have been from a Stephen King collection or an anthology presented by Stephen King.
Could it be The Colour Out of Space by H.P. Lovecraft?
The story involves a man in a cabin, an alien force that has infested the nearby well, and in the end his dead horse is found as remains.
The full story can be found here.
Apologies for the stump answer. Unfortunately not able to provide more details at the moment.