Both our children's nightlights 2009 onwards were these 0.5W LED mains plugs, a tiny 1/10th the consumption of the incandescent type that we used before. Note that they don't actually seem to draw less power when they turn off in daytime, and we turn them off manually anyway.

We're very happy with these robust lamps.

Note: even the puny 0.5W these consume is horribly inefficient in that the vast majority is being turned into heat rather than light.