2 Nephi 32: 3 Angels speak by the power of the Holy Ghost; wherefore, they speak the words of Christ. Wherefore, I said unto you, feast upon the words of Christ; for behold, the words of Christ will tell you all things what ye should do.

This is another clue as to who or what is the Holy Ghost. From what I have observed, angels who watch over us and speak to us are usually relatives from our past or our future. They are working out their salvation as they guide us in working out our salvation.
This is just what I have observed from stories of people who have had near death experiences-I'm not going to quote any scriptures on this. This would corroborate what Son of Zion said to some degree-that there are many Holy Ghosts in a sense. This would also go along with the thought that the Light of Christ fills the universe.