Has anybody read Graham Greene's Our Man in Havana? A vacuum cleaner salesman in Cuba is in need of cash. He gets it by agreeing to help British Intelligence but because he has no real secrets to sell, he makes sketches of vacuum cleaner parts and says they are secret Cuban military installations. The only people in MI6 who don't believe it keep their gobs shut because they don't want to get fired. People die.

Written in 1958.