For children, it can be comforting to have a night light to make the room a little less dark at night. As an adult, you might appreciate being able to find your way through your home at night without stubbing your toes on something.
Night lights have been used for decades, and they have gone through a few upgrades. Where it used to be just a plain lightbulb that you had to unplug during the day if you wanted it off, they now come with motion sensors so they light up when you get near, or they turn on and off on their own if it gets light out.
It is important though to avoid getting a nightlight that could be harmful. A poorly build nightlight could easily start a fire, so you should make sure that you get something that feels sturdy enough that it won’t fall apart on you after a few months. As with most things, you should be able to find something online that comes from a reputable seller and that has ratings you can compare.