Dim Interior Lighting (Easy Fix - NOT a glitch)

Another thing that helped me was to click on a light and turn on all the lights in the house, then go to the bedrooms and set auto-lights in there. This was an old trick from TS2. If you have all the lights set on auto-light, they don't come on during the daytime at all and it makes it seem dark (and made TS2 Sims unhappy with environment). It makes a huge difference to have them on in the daytime.