Preparing for the Big "Switch-On" Workmen are now engaged in many parts of the country in preparing electric signs in readiness for 2nd April when the ban on the use of electricity for outdoor advertising and shop window lighting is lifted. In Piccadilly Circus, London, many of the signs will spring to life once again for the first time in 10 years. Photo Shows: Electricians at work on one of the huge signs in Piccadilly Circus, London, S.W. 23rd March 1949