Ghostwriting jobs are a way to make a living as a writer but you have to be willing to do some things that some writer's don't appreciate.
As a ghostwriter you have the chance to write books, speeches, scripts, and other types of writing formats for people. The pay range varies but you will often not get public credit for your work. If you are willing to put together a story for someone else and have them get credit for it, ghostwriting might be a career for you.
Most celebrity autobiographies are done with a ghostwriter. The celebrity is often someone who wants a book but doesn't want to write it, doesn't have time to write it, or doesn't know how to write a book. They (or the publisher) will hire a ghostwriter to write their story for them. If you are reading a book and there is a "with" next to the name of the author, then the "with" is the ghostwriter. That is the person who wrote the book.
Since I have become interested in learning more about ghostwriting (and possibly becoming one) here is the information about it I have learned:
Become a ghostwriter can be done in a few ways but usually they require you have some published work and have built a reputation as an effective writer. If this is the case you can do freelance ghostwriting or if you can get hired by a publication you can do ghostwriting when they publish celebrity books or novels.
As far as the work goes, a ghostwriter will meet and interview whoever is being listed as the author. They will have to get an understanding of not only what the author wants to say but how they would express it. Research of the author's field of work might also be necessary in some cases. Ghostwriting costs vary and some get paid by the project, some get paid by the hour, and others get a percentage of revenue the book makes.
Writing is a challenging career with a lot of competition and it's tough to make a living as a writer in either fiction or non-fiction but if you are willing to put your ego aside then ghostwriting might be for you. It sounds like there is a good market for ghostwriting and I expect that will continue. If you want more information look up The Writing Show Podcast and listen to episodes 154 and 155. Author Eva Shaw, a ghostwriter, also has a few books out on the topic.