For starters, both narrators are considerably unwell. They are classic examples of unreliable narrators since we see the world through only their eyes/perception.
The Yellow Wallpaper narrator is mentally ill and becomes more and more deranged as the story progresses until she is creeping around the room--even climbing over the fallen lump who is her husband.
The Cask of Amontillado narrator plans with malice and premeditation the murder of his victim. He entices the victim, already drunk from the celebration, with the rare wine and then once the victim is in the cellar where no one can hear him scream, the narrator bricks him into the wall and leaves him there.
In terms of unreliable narrators, the two stories are similar. In "The Cask of Amontillado," the narrator, Montresor, seems to be confessing to the murder of Fortunato, possibly on his death bed, but the reader is never really sure what is real and what has been fabricated by Montresor over the 50 years since the crime happened.
In "The Yellow Wallpaper," the narrator is also unreliable. We get snippets of her story from a journal she has been keeping that chronicles her descent into madness at her confinement in an upstairs bedroom at a house she and her husband are renting for a few months. Throughout her narration, the reader becomes aware of several things that the narrator is not aware of, like her descent into madness. Since she is losing her grip on reality, we too much question her take on the events in the story like one might question Montresor's interpretation of the events in "The Cask of Amontillado."