While praying one day it occurred to me that too often the word "spirit"was used without the word "holy" preceding it and that the "evil one" hearing the call might respond to the open ended invitation. At the time the Church in my diocese was in crisis and the thought that some of it might have been "by invitation" made sense to me. Almost unconsciously I found myself saying Holy Ghost,even in the Creed at Mass.
I can only say my prayer life improved and I felt much less unsettled.Furthermore,several years later (about eight months ago) we got a wonderful new Bishop. You just don't forget Holy and call on the Ghost,or the Ghost of Vat II or the Ghost just a blowing through the Church----it just doesn't happen.I think when you call on the Holy Ghost,He knows you're talking to Him,the third person of the Trinity.