A bit of aerial theatre from Dan Todman's (excellent) Britain's War: Into Battle, 1937-1941:
Newton Abbot, Devon, February 1941. The town is holding its War Weapons Week to promote the National Savings movement. It has been set the aim of increasing savings by £100,000 during seven days. To publicize the event, local organizers arrange a fly-over by RAF bombers from a nearby airbase. They drop 10,000 advertising leaflets, with instructions about how to take part in the savings drive. Each is headlined 'THIS MIGHT HAVE BEEN A BOMB'. Whether this is a plea or a threat, it works: Newton Abbot smashes its target, with £216,000 invested by the time the War Weapons Week ends.1
Unfortunately, I haven't been able to find a picture of one of these leaflets, or evidence of their use elsewhere in Britain, but the same phrase was used in other leaflets dropped on Hamilton in Ontario, Canada, in the very same month, by a member of the local aero club as publicity for War Savings Certificates:
The leaflets dropped on Newton Abbot may have been something similar, though the message here is obviously slightly different ('help destroy Hitler's murderous bombers ON THE OTHER SIDE OF THE ATLANTIC') -- and would be different again when dropped on Reedsburg, Wisconsin, in January 1944 by the Civil Air Patrol ('Join the Womens' Army Corps') and when dropped on Los Angeles in December 1951, again by the Civil Air Patrol ('These could have been REAL BOMBS! EVEN A-BOMBS!') A little bit of aerial theatre travelling a long way.
Daniel Todman, Britain's War: Into Battle, 1937-1941 (London: Allen Lane, 2016), 603. The source is given as TNA, NSC 7/78, 'War Weapons Weeks: Items of Special Interest'. ↩