This false trap is designed to fool a thief or other character attempting to pilfer the spellcaster's goods. The wizard places the spell upon any small mechanism or device, such as a lock, hinge, hasp, screw-on cap, ratchet, etc.
Any character able to detect traps, or who uses any spell or device enabling trap detection, is 100% certain a real trap exists. Of course, the spell is illusory and nothing happens if the trap is sprung; its primary purpose is to frighten away thieves or make them waste precious time.
The material component of the spell is a piece of iron pyrite touched to the object to be trapped while the object is sprinkled with a special dust requiring 200 gp to prepare.
If another Leomund's trap is within 50 feet when the spell is cast, then the casting fails.