I accidently deleted the fusebox in one of my homes and I can't find it anywhere on the store. Why would you be able to delete it if you could replace it??? :(

Just proceed decorating the house as normal. Buyers don't care about lights being on or off.

Have you turned off the day/night cycle in the gameplay options? This makes it permanent day in most of the houses. Or permanent night in others. If not, log out of the game, log back in to reset it back to morning, and then turn the day/night cycle off, so that you have enough light.

If the deleted fusebox is in a job order (very unlikely) these can be restarted.