I also believe they are the same. I find that in the more modern translations He is dubbed the "Holy Spirit" throughout. In the KJV it's like half and half in a way. I do believe it is the same thing though.
And also, if there were two different Holy "entities", then there would be a issue in the Word:
For we were all baptized by one Spirit into one body—whether Jews or Greeks, slave or free—and we were all given the one Spirit to drink. 1 Corinthians 12:13
Yes, the English translations "Ghost" and "Spirit" are of the same Greek word.
The KJV translation was "Holy Ghost" - but that was way back in 1611. Trouble is the meaning of the word has changed since. So the One Who lives in me and you is NOT a "ghost"!!
If we want to truly communicate with today's people, AND be living in 2009, we really should stop using "Holy Ghost" and use "Holy Spirit". (As a bit of a "shhh!" I do have to suspect that many preachers use "Holy Ghost" because they think it sounds more spiritual to their congregation. Shhh!! I didn't say that, okay...)
I (like John the Baptist) get the same feeling when I think of the Goodness of God, Christ and the Holy Spirit.
Luke 1:41. And it came to pass, that, when Elisabeth heard the salutation of Mary, the babe leaped in her womb; and Elisabeth was filled with the Holy Ghost:
We need First to have JESUS, thus we are assured the comforter, which is His promise (His spirit). Once Glorified, we are acceptable/Justified to God.
John 14:26. But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
Ephesians 1:13. In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
The answer to the original question is Yes. However, this difference can only be observed in a written form; i.e. the difference exist only in the spelling. Thus, we are given liberty to use either (Spirit or Ghost).