So I'm a little curious about how the whole ghost writer thing works, and the kind of relationship that they would have with the person they work with.

Is anyone here a ghost writer? Or does anyone know much about this and how it works?

So there are a few things I'm wondering. For starters, do they care about the story as much as the original creator does? I feel like authors and writers care a lot about their stories and characters, so I don't see how an outsider could care about it in the same way.
What's the difference between a ghost writer and a partner? Or do ghost writers often become an authors partner and only work with that one person?
Do they just write a lot of different people's stories or usually only help with stories that they take an interest in? Is it just a job and something money focused or is it interest focused?

Also, I apologise if I'm using the phrase ghost writer wrong, and if it's not what I think it is.

The scenario would be a writer who's not very good with words and the writing of the story itself, but has a lot planned and a lot of ideas that they really want to bring life to properly. I'm not talking about unrealistic whims, or only half thought through ideas, but something big that they've been working on and developing for even a few years.
Now lets say that they have decided that they need help with it, and have tried many times in the past to write it but just can't get it right, like they're missing something or that their area of expertise and focus lies elsewhere. The problem is that they care so much about their stories and characters and the overall project that they don't trust it with just anyone. They really wish that they could do it on their own because they've gotten so far into expanding it that they feel like it's very late to start explaining everything to someone who would help them, and would have no idea how to find someone to begin with.

What usually happens? Maybe I went in to too much details but how would simpler or similar situations be handles? Let's say this scenario wasn't professional either, just a first work from a nobody, there wouldn't be a way to be able to take them seriously enough would there? Or maybe better phrased, there wouldn't be a way for them to know enough about them or their story, to know if they wanted to work with them.

But anyways, if someone could explain a bit more about how ghost writers and partners are found and how serious the relationship between them is then that would be much appreciated.

I guess the simple question I'm asking is this: Are ghost writers/partners not meant for someone who cares too much about their stories?