Our Man in Havana (1959), produced and directed by Carol Reed.
In Cuba around the time of the revolution (and shot on location then) a mild mannered English shopkeeper is approached by the local British spymaster. He has no interest in spying, but has a grown daughter who needs things. Lots of things. So: just make up some exciting facts and sell them. What's the harm?
Then they send him a staff and his fictions begin coming true. It is now a dangerous game and he actually becomes what he never planned: a real secret agent with a gun.
This is an odd little film, witty and satirical, but approaching the edge of danger and grim reality. Inventive casting:
Comedian Ernie Kovacs as the affable but sinister police Captain. ("Some people expect to be tortured, others are outraged by it.")
Burl Ives as a German doctor.
Maureen O'Hara as a British secret service operative.
Alec Guinness seems very natural as a vacuum cleaner salesman with a busy imagination, and Noel Coward as an upper crust clownish spymaster: of course.
I noticed a repeated bit of business from The Third Man (1949): when meeting a policeman on the sidewalk you step into the gutter.
Novel and screenplay by Graham Greene.