Glory be to the Father and to the Son and to the Holy Ghost!

Great reflection on why Holy Ghost might be preferable to Holy Spirit in this day and age by Taylor Marshall. Here's an excerpt.:

There is also two theological reasons for using "Holy Ghost" from time to time. 

1) First, we live in a culture where being "spiritual" is increasingly popular and increasingly vague. Just think about that horrid song "Spirit in the Sky," and you know what I mean. In neo-pagan parlance, "being spiritual" and "the spirit" have nothing to do with the personal God fo the Sacred Scriptures. This "spirit" is more like "the force" in Star Wars than it is the Third Person of the Blessed Trinity. So when you say "Holy Ghost," you're clearly referring to traditional Trinitarian theology.

2) In English, "spirit" has always had a vague meaning and this is likely why the translators opted for "ghost." Spirt is not wrong. In fact, the Latin spiritus is almost identical to the Greek pneuma. But spirit in English can refer to abstractions or it can refer to a person.
Examples: 

"We've got spirit, yes we do! We've got spirit how 'bout you?" Spirit, here, refers to vigor and enthusiasm. Nobody assumes that the cheerleaders are possessed by a "ghost" or "spiritual being."

 "the spirit of Vatican 2"

I think every magisterial Catholic from Pope Benedict XVI on down knows that the so-called "spirit of Vatican 2" is certainly not the "Holy Spirit." Here, "spirit" refers to a way of interpretation or a movement.

"Play this song with spirit!"Here again, this doesn't mean to invoke an immaterial person. It means to play a song with a certain tempo or feeling.
So then, "spirit" can be ambiguous. Ghost is not ambiguous. Ghost always refers to "immaterial person."

So when people speak of the Holy Ghost, the orthodox theology of His status as a Divine Person is highlighted. .