Maybe small focus on the windows? Ghostly faces, curtains and like. Even laundry drying on poles.
I agree, especially curtains. You might also put a 'light in the window'. Not necessarily
actual electrics, but paint to suggest brightness. Yellow, either thinned or translucent
like Tamiya's, might do it. Also don't do every window.
You could go even further. Get an image of a Victorian oil lamp, paint it up & stick some
of them in various windows.