“The Yellow Wallpaper” and “The Tell-tale Heart” have in common gothic elements, unreliable narrators and portraits of mental illness.
Both stories are very gothic. Gothic elements include things that make the story dark or spooky. In this case, the madness adds to the gothic nature of the stories. So does the setting. The yellow wallpaper and the house both seem spooky. They make the reader uneasy. Mentions of the vulture eye and the woman trapped in the wall are gothic and disturbing.
Each story has an unreliable narrator. An unreliable narrator is one who cannot accurately describe the events of the story due to madness or youth. In this case, madness prevents either narrator from describing what is happening in a realistic way. Instead, all of their observations are colored by their madness and we don’t know what do believe. Notice that neither narrator has a name. This adds to the uneasiness and distance.
“The Yellow Wallpaper” and “The Tell-tale Heart” do both involve narrators who suffer from mental illness. In each case, the narrators themselves don’t seem to realize it and arguably neither does anyone they interact with, until it is too late. The old man clearly does not see any risk in the narrator in “The Tell-tale Heart,” and the narrator’s husband in “The Yellow Wallpaper” does not seem to realize how far she’s gone until he sees her crawling the walls and faints.
Both stories are told in the first person, through the eyes of a mentally ill narrator who is unaware of the extent of his or her illness—though aware that others think he or she is ill. Both stories focus on describing interior or psychological states rather than objective reality, giving the reader a glimpse of what the world might look like to a person who is mentally ill.
In "The Tell-Tale Heart," the narrator becomes fixated on the eye of the old man he cares for and with what he believes is the sound of his beating heart. He feels he has to shut the man's eye and stop his heartbeat no matter what, so he murders him. Likewise, the narrator in Gilman's story is fixated on the yellow wallpaper in her room. She believes it looks like eyes staring at her in places and that a woman crawls in the pattern. She tries to tear all the paper off the wall.
In both stories, the narrators create narratives to explain their situations that appear quite reasonable to them but reveal to the reader the depth of their irrationality.