I share a flat with two other people because there are three rooms there; so each person has a room to himself. Recently, the electric bulb in one of the rooms got burnt and the lady using the room for some reasons was not able to replace it.
So, she begged me to always let her know when there was power supply in the midnight so that she could plug her rechargeables. I am a deep sleeper myself but direct light can interrupt my sleep so what I do is turn on the light bulb in my room. When power supply is restored at midnight, the rays shine too brightly over my face and it helps me know so. So I usually get up, knock on her door and notify her that power has been restored.
However, recently, she had a visitor who I guess was her cousin. When it was time to sleep, my flatmate reminded me again not to forget to wake her up in case power is restored at night. The cousin asked if she had no bulb in her room and she explained that the bulb had burnt and she had not replaced it because she always forgot. The cousin then said they didn’t have to bother me. She brought out her charger and plugged it into one of the sockets in the room- the one directly facing the bed. It appeared that her charger had a little light on it that turns on to indicate that the charger was appropriately connected to light source anytime it is connected.