How to cure a ventriloquist

Did you ever hear the story of the ventriloquist who played solitaire? He used to annoy his wife by holding long conversations with himself in his sleep. It became such a trial to the poor woman that she had serious thoughts of getting a divorce. And then one evening, by the greatest good luck, he caught himself cheating at solitaire and never spoke to himself again.

(from Doctor Sally, by Sir Pelham Wodehouse)