The term ghost refers to a previously incarnated creature who somehow lingers around after death, and I don't think they are any more holy in death than in life. Anything that reflects the Creator is sacred and in that sense Holy. The Holy Spirit is essential to the Holy Trinity, the nature of which is widely debated within Christianity. HS seems to represent the most mystical aspects of the Creator. Jews don't worship the HS because their faith is given to an undivided Creator that embraces everything within itself.
R: Since none of this was originally recorded in English, my best guess would be that "ghost" is someone's lose translation, and nothing more, but I don't know.