I used to do quite a bit of moonlighting in various hospitals, ERs, and ICUs. Now, I just sit back at home, open up my laptop, and type. This is my moonlighting. I'm not making as much as I did back then, but I get to stay at home, drink some green tea, watch TV, relax, spend time with my family, and enjoy life. Isn't that much better?
Blogging is my 2nd job. But I don't see it as work and it's more than a hobby. I have specific passions and I enjoy writing about them. If I can make a small amount of cash from it, then fine. I'll let it pay for my gym membership.
Do you have a passion? Why don't you start writing about it? You may really enjoy it.