He does not have a name. When you call Him Holy Spirit or Holy Ghost, you are just describing Him that He is a Spirit, or a Ghost that is Holy. That is a description of His character. These are titles and not names. He has no name because He was sent in the Name of Jesus and operates in the Name of Jesus (Jn. 14:26). When you call the Name "Jesus Christ", the Holy Spirit goes into action. He was sent by the Father in the Name of Jesus Christ. He has no name of His own, but answers to the Name of Jesus. It is His presence that leads to the acknowledgement of Christ's Lordship (I Cor. 12:3), Spiritual power (I Thess. 1:5), inward joy (I Thess. 1:6), moral purity (I Thess. 4:7-8), and an inner witness of being God's children (Rom. 8:15-16, Gal. 4:6). In fact, without the Holy Spirit who dwells in a believer as in a temple (I Cor. 3:16), you cannot be a Christian or continue as a Christian. He is a promise to every Christian. He is given to all, not to some as a reward for their obedience (Acts 1:5, 2:4, 4:31). If we do not have the Holy Spirit, we are not Christians (Rom. 8:9, Jude 19).