The most common people looking for work from home opportunities are stay at home parents so take a look at sites for that. These usually have a section for jobs for parents, whether they are part-time or flexible hours in the office or work from home possibilities. Look through the job boards to see if there is anything that jumps out.
However, be aware that people will still post fake jobs to get your money. Check out the requirements before signing up to any site and make sure you do not need to pay money. They may want samples of your work or to do a trial to make sure you can do the job but genuine ones will pay for this; just like a trial period in a workplace.
