What are the different similarites between "The Yellow Wallpaper" and "The Cask of Amontillado".
Your question is confusing. Do you mean "What are the differences and similarities . . ."? Or do you mean "What are the similarities for the different stories"? I'll go with the latter.
One of the similarities between them is that of the unreliable narrator. For the wife in "The Yellow Wallpaper," since she is slowly descending into madness, we are not sure what she is telling us is even true. Plus, we are able to realize things about her plight that she doesn't, such as how she is slowly becoming obsessed with the wallpaper and descending into madness. In "The Cask of Amontillado" the narrator, Montresor, is also unreliable. Since he is recounting the tale many years after it has happened, we are not sure what we can believe and what he has fabricated.
Another similarity is the element of suspense. Both stories build up suspense. In "The Yellow Wallpaper" we are kept prisoner along with the narrator. Will she escape? Is the house haunted? Who is the woman trying to creep out from behind the wallpaper? In "The Cask of Amontillado" we are kept in suspense about the punishment Montresor has in store for Fortunato. What could he have done to Montresor to offend him so? Will he escape? Will the narrator change his mind and forgive him? Will he get away with it?