Can a foreign teacher with a work permit teach privately at home in Thailand?

The question discusses the legality of foreign teachers in Thailand teaching privately at home while holding a work permit for a school. Community responses reveal conflicting opinions: some assert it is not legal unless it's for the same employer or in very small amounts, while others suggest that many do it without repercussions. A consensus forms around the idea that while it may not be officially allowed, discreet private tutoring is common if not conducted as a business.