Question: A man fell seriously ill. He visited many doctors but they could not cure his illness. When he went to a man who is in the habit of making Tawassul (supplicating to Allaah through a means) by the dead and seeking their help and blessings, Allaah cured him. Is it permissible to go to such a person? This incidence happened many times to the point that people believed that such a person treats the sick through these acts of Shirk (associating others with Allaah in His Divinity or worship), we seek refuge with Allaah! What is the ruling on this?
Answer: It is forbidden to go to someone who practices acts of Shirk, such as making Du`aa’ to and seeking help from the dead for the sake of recovery from illnesses… read more here.