Something that seems mundane or everyday, could be the seed for an intriguing story. Often horror or thrillers use the familiar and give them a spin to unsettle and make the everyday something out of the ordinary. Think of the wardrobe, leading to Narnia and the television, in the film Poltergeist.
Your writing prompt: Your character is scraping wallpaper off the wall. One sheet peels off to reveal the old wall or perhaps another layer of paper beneath and they notice some writing. What does it say? Is it a message, a warning, a spell, a map? What happens next?