It made no sense

It made absolutely no sense for these families to hire Charles. In season 1 Mr. and Mrs. Pembroke were both around the house. From season 2 on the Powells had both the mother and the grandfather in the house. The grandfather wasn't some invalid, he was quite capable of handling things. Why pay this guy money to have him mooch around the house with his friend Buddy there, always helping themselves to the fridge? It seems like quite often he was trying to take the night off to go on some date anyways.

The only plausible explanation would be that Charles was some sort of undercover agent stationed in that town and the families were told by the government to accommodate him. Then again, that would be unconstitutional.