Was there an episode about a house fire?

Not sure about the paint, but there is an episode I just watched where Victor kicks over a space-heater while in his boarding house, later causing a fire.

There was also an episode where they guise as a pair of painter / decorators so they can gain trust and get access to a family home under false pretences.

There are no fires caused by cheap paint however and their dishonesty is somewhat balanced by teaching a young lad not to be a racist (towards his half sister).

In fact the episode may have inspired the love plot in Rambo: First Blood Part Two although I cannot say with any certainty whatsoever whether this show predated that particular film.