Your question appears to refer to a short story titled "The Landlady" by Roald Dahl. In this story a seventeen-year-old young man named Billy Weaver has been sent on a business trip and needs to find a room to rent for the night before his morning appointment at the office. Billy has heard that there is a cheap hotel called The Bell and Dragon that may have a room available, and he sets off to find it. On his way, he stops in front of a shabby house that has a sign in the front window indicating that it is a bed and breakfast. As the reader gradually will realize, it is a story full of deceptions.
One thing that is not what it seems to be is the look of the house. The exteriors of the houses on this street are described as having paint peeling from their woodwork and that their "handsome white facades were cracked and blotchy from neglect". But when Billy peeks inside the window of the bed and breakfast, he sees that the inside appears warm, peaceful, and cozy.
Another pair of things that are not what they seem are the parrot and dachshund present in the front room. They seem to be peacefully sleeping, but they are actually dead and preserved by taxidermy. The dachshund, in spite of being positioned in front of the fireplace, is actually hard and cold when Billy touches it later.
The most important thing that is not what it seems is the landlady. In Billy's opinion she seems harmless and motherly. He thinks that maybe she has lost a son, and this is the reason for her treating him so kindly. He thinks she is a little bit "dotty" (eccentric). Actually, she is very much so. And her kindness is definitely not altruistic. As will be revealed by the end of the story, she is predatory and homicidal. Billy is feeling so welcomed at first that it takes him a long time to piece together the clues about the fate she has planned for him. These clues include her odd manner of looking at him from head to toe as if appraising his body, her strange odor of something like pickled walnuts or leather, her repeated comments about Billy's perfection, and the hauntingly familiar names of the previous two guests in the landlady's guest register. The landlady goes so far as to lie when Billy questions her about the names of the guests, claiming that her Mr. Mulholland could not possibly be the same one whose disappearance Billy had seen in the newspaper.
And lastly, we realize that this comfortable, cozy home is in reality a place of dark evil, a beautiful spiderweb that has attracted and then ensnared the naive Billy. Its homey interior appearance clashes with the run-down features of the outside of the building, and the true nature of what happens there clashes with the expectation of safety that Billy had when he entered it.