I don't recall the author or the title but the plot revolves around a bank-built house in a mountainous forest discovered by a lone traveler. In the house is a painted portrait of the same house hanging on the back wall, which is covered by a tapestry or wall hanging of some sort.
The wall or tapestry hides the entrance to a cave or tunnel from which all manner of horrors eventually emerge. The portrait of the house is closely examined by our traveler and is described in minute detail by the author.
The list of probable authors include H. P. Lovecraft, August Derleth, Clark Ashton Smith and Robert Bloch.
I believe it was a Cthulhu Mythos collection that contained it but I have had no luck finding such a tale on line or in any book that I currently have access to.