What is the Sharia ruling on seeking refuge in a man who interprets visions and treats illnesses with the help of jinn, knowing that he does not err in his interpretations or treatments?

There is no definitive ruling regarding seeking help from jinn. Some scholars have permitted it for lawful matters, while others have forbidden it due to fear of their evils and deceit. It is more prudent to avoid them because their conditions and the truth of their faith are unknown, and because there is no evidence that the Prophet, peace and blessings be upon him, or his Companions, or the Tabi'in sought their help. Scholars have recommended avoiding them and not seeking their assistance, even in beneficial matters.