Long corridors can be intimidating to walk through especially for people who are new to a place. Examples include hotels and other public places that have guests well into the night. It makes sense for the establishment to install wall lighting fixtures that can make a dark path a bit brighter. These lights can serve as guide for people who are looking to go back to their rooms.
While it is true that overhead lights are also possible, there is no reason why wall lights cannot be added into the mix. These fixtures can function both as illuminating devices as well as decorative items, and sometimes both in the case of painting with two of them at the sides. They are, after all, closer to the ground and can be placed within eye level making them a more effective source for this application.