During the plague of darkness, who had light where they lived?

Answer: The Israelites

Total darkness covered Egypt so no one could see anyone else, "yet all the Israelites had light in their dwellings."

“So Moses stretched out his hand toward heaven, and total darkness covered all the land of Egypt for three days. No one could see anyone else, and for three days no one left his place. Yet all the Israelites had light in their dwellings.”— Exodus 10:22-23 (BSB)