A spirit is a ghost. I'm not religious or a spiritual person but yeah to me a 'Spirit' would be a ghost.
Or the thing that defines somethings energy as in "get in the spirit of christmas".
I'm talking about in the context of religion, not the paranormal. The other example is not literal, but poetic.
What is the force, from Star Wars, to you when hear it?
Well, it's a fictional Universe so I don't see the connection at all to be honest. It's like asking me why Superman can fly.
In this fictional Universe, there is some natural force called "the force" which binds together everything.