The shadow in my childhood home always smelled like ozone and old books.

When I was a child, a tall shadow would sometimes appear in my doorway at night. It never moved or spoke, but the air would fill with the distinct smell of electrical ozone and dusty paper. Years later, I learned the previous owner was a radio repairman who collected antique books. My parents never believed me until my mother admitted she sometimes smelled old books in empty rooms.