What is the ruling of the Sharia on using the method of placing a key inside a Mushaf and reciting Surat Ya-Sin to uncover a thief?

It is forbidden to go to anyone who claims knowledge of stolen or lost items, or of who stole them, by any means whatsoever, such as divination, fortune-telling, sorcery, and the like. This is because these are false claims based on lies, and often involve seeking assistance from jinn. Anyone who does this claims knowledge of the unseen, which Allah has reserved for Himself. The Prophet, peace and blessings be upon him, said: "Whoever goes to a fortune-teller and asks him about anything, his prayer will not be accepted for forty nights."