If you have a 240v 4 wire circuit (hot, hot, neutral, ground) and the 30 amp breaker it currently has was replaced with a 20 amp breaker, is there a code confirming way to "split" the hots at the outlet to provide two 120v 3 wire 20 amp circuits? I'm thinking some sort of adapter must exist to do this, unless there's a safety reason why this would be a bad idea.