Minecraft wiki entry for Hiding_chests, associated text: Find a dungeon and hide it (Tutorials/Secret door). Attach a redstone lamp to the monster spawner and set up the redstone so that the lamp is on when the door is closed and off when the door is open. This ensures that no mob noises can be heard while a thief is searching, and that they will guard if they find the dungeon. Hide important items in here, and they will be safe.