We are not told in the Bible (or, as far as I am aware, in any other historical records) how Gehazi1 died.
1. Gehazi was Elisha’s servant. He first appears in the Bible in 2 Kings 4 (v12).
– Did Gehazi still have leprosy in 2 Kings 8:4?
– Is “leprosy” in the Bible the same as the disease that’s called leprosy nowadays?