One of the posts here mentioned hiring ghost writers. I never have but you might check Writer's Digest (and those type of publications), for I believe there are some posted in the classifieds. However, I cannot recommend anyone or any source in particular, but I'd be sure to get refs. so you find a good one. Also, you might contact a writers org. and see if the president can recommend anyone.
There are Sisters In Crime, Romance Writers of America and Mystery Writers of America. Even though they're in specific genres, often they cross over into other areas and can write about anything. Again, do your homework in order to find a good one.
Best wishes in your writing endeavors, everyone!