Posted by TC (361 days ago)
No you're not an employee in those circumstances, but you are classified a volunteer engaged in unpaid employment. Splitting hairs, I know. But the good news is that if you approach the Immigration Dept and ask nicely I think they would grant special permission provided that the charity is registered and has a good reputation, plus both parties sign a declaration that there will be no payment for the work undertaken. Good luck.
(I am based in Hong Kong)