By day, Robin O’Neal Smith is a chief information officer for a local school district. After hours, she is a ghostwriter and editor for bloggers. Smith now earns about $1,000 in extra cash every month from the side gig she launched two years ago. “I had started a business to do social-media management but there seemed to be a much higher demand for blog posts than Facebook and Twitter,” said Smith, 56, who lives in Pennsylvania in the US. “So…