Compared to the 1950s, the biggest cause of changes to domestic electricity use in the UK wouldn’t be TVs and lightbulbs, it would be double glazing, cavity wall insulation, and loft insulation (for electrically heated houses, which certainly isn’t all of them), microwave dinners replacing Sunday roasts (at least, in so far as 50s UK stoves and hobs were electric rather than gas), and showers replacing hot baths.

That said, IIRC the main electricity users in the UK are business rather than domestic, and I don’t know anything about how that’s changed in the last 70 years, only that it has.