I found a wonderful collection of miscellaneous bits of BBC folk lore. One of these reads as follows... "While carrying out some audience research in 1958, a researcher called at a house and was greeted by a young woman with a toddler at her side. The researcher started, ‘Good morning, I’m from the BBC …’ upon which the young child screamed and ran down the passage. The woman apologised for her daughter’s behaviour but explained that she had taken to switching the television set on and off. Her mother had said that if she did not stop doing it, the BBC man would come around - and he did!" Read the collection for yourself. here.