Legitimate jobs working from home is something that is important to locate as there are a number of scams out there. Always be sure that when you son decides on a particular job from home that no money is sent upfront as the company should never allow this as that would show that they are not one to work with.
Ghana News has a good article on finding work from home jobs and a link to a site that can be helpful:
Clark Howard who is a consumer advocate offers a quality list of legitimate jobs that can be done from home. Some are looking for international help so best to send to your son to see if there is any interest in any of these jobs:
Inquire then with this list of companies as they are accepting applicants worldwide: