Another option to earn money and improve your writing would be to become a beta reader. I've seen them on a freelancing website. As a beta reader, you read and provide your opinion to the writer. If the writer has specific questions, you'll do your best to answer them.
If you do ghost writing, there are also different approaches to it. Some writers give a detailed outline for the ghost writer while others give a more broad description. Some will give the ghost writer a draft, finished or completed, and ask the ghost writer to rewrite/finish it. I came across a vid a few days ago about ghost writing from a ghost writer, hope this helps: