This expression -- meant to denote someone's stupidity -- was ubiquitous when I lived in the Anglo-world. I imagine it still is today. However, I don't think it really applies anymore. In fact, I think the inverted form of this expression represents the current state of the world far more accurately:
Someone's home, but the lights are out.
Or, more even accurately:
Everyone's home and the light is on, but nearly all have blinded themselves to it.