In Ray Bradbury's celebrated short story "There Will Come Soft Rains," a completely automated smart home in Allendale, California continues to perform its routine mechanical functions in the wake of a nuclear holocaust, which has decimated the surrounding city and killed the entire family. At the beginning of the story, the smart home ushers the family to wake up. It makes breakfast, issues reminders, and sends robot mice to clean the home. Despite maintaining its efficiency throughout the home, there are no humans alive for the house to please. The technologically advanced home is said to have "kept its peace" and remains on alert for intruders. Bradbury writes,

How carefully it had inquired, "Who goes there? What's the password?" and, getting no answer from lonely foxes and whining cats, it had shut up its windows and drawn shades in an old-maidenly preoccupation with self-protection which bordered on a mechanical paranoia.

Bradbury personifies the home as experiencing "mechanical paranoia" by referencing its irrational fears and delusional concerns regarding possible intruders. The reader recognizes that in the wake of a nuclear holocaust, there are no possible intruders and nothing to fear. By carefully inquiring about the presence of every animal and responding to any outside noises, the home imitates a paranoid individual. The automated home also responds to outside noises by shutting and locking every window and door, which underscores its "mechanical paranoia." The narrator also mentions that the home "quivered at each sound" and would not even allow a bird to perch on a window.

The smart home's emphasis on self-protection and irrational fear of intruders illustrates its "mechanical paranoia." By describing the home's "mechanical paranoia," Bradbury contributes to its personification and accurately conveys the home's primary concerns, which are to protect and serve the family.