Through flexjobs.com (internal link) I found out about two sites promising to freelance writers. I was unable to complete the application process for either of them for different reasons, never-the-less, I think they are both worth checking out:
Ellipsis (external link) seeks writers to be the written and social media voice of a company. Having a varied and published writing background seems important to them. Hours vary, depending on what client you wind up representing. They seem apologetic about the time it takes to respond to an application but I did not find the waiting time unreasonable. Unfortunately, due to a momentary crush of work from my main employer, I was unable to complete the application process for Ellipsis. I regret that inability but my loyalty has to be first and foremost to current clients. Do look into Ellipsis if you are searching for a creative and intriguing job opportunity.
Ask Wonder (external link) is another site I found through Flexjobs.com. At Ask Wonder, you are assigned questions to research for clients. Those questions could be on almost anything. Perhaps someone needs to know how many cat sitters are in New York City. Or how rainfall affects construction sites in Patagonia. Whatever. I found, though, that their sample writing test would take me much longer than the suggested 90 minutes. For me, probably 2 1/2 hours. I’m a careful researcher but I am also slow. Taking that long to answer a question would probably have me working for less than $10 an hour, although, to be truthful, I do not know what they pay. Knowing how poke-slow I am with original research, I respectfully bailed out of the hiring process. But, again, I would urge you to check them out if you are interested in varied and flexible work.