As has been said, it's usually a closed shop with jobs put together by a publishing house. The editor puts the celebrity with a writer who has a solid track record of delivering publishable copy on schedule.
Ghost writing a novel for a regular person who has ideas but no writing skill is much trickier. For one thing, most won't have the money to afford a ghost writer. I've seen info where they get paid 15-25K to write a book, but Auntie Murgatroyd who wants someone to write her cozy mystery likely won't have that much cash in the sock drawer, nor will her mystery get more than 1-5K as an advance.
Of course, you can check out Craig's List but getting a job slinging burgers has more benefits and will be less frustrating.
One of my friends got stuck writing a techno-thriller for a dude with more connections and money than sense.
She wrote an amazing opening scene that had soldiers running for their lives as a reactor melts down, terrible things are happening, foreshadowings of more thrills to come were there. It was kickass and you wanted to see what happened next.
The dude told her to scrap that and open the book with the hero fixing his car. In detail. Right down to where he ordered the parts, what kind of pizza he had for lunch, and how tough it was to find a certain kind of steering wheelzzzzzzzzzzzz.
He signed the checks, so she did what he wanted and made danged sure that her name did not appear on any line in that manuscript.
Ghost writing may seem a good way to make some cash, but you have to be able to write what the client wants, turn it in FAST, and not care if they change things for the worse. The closest I got to it was doing work-for-hires. Never again!
