A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or during an emergency. Small long-burning candles serving a similar function are referred to as "tealights".
An LED nightlight
A light fixture, light fitting, or luminaire is an electrical lighting device containing one or more light sources, such as lamps, and all the accessory components required for its operation to provide illumination to the environment. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for easy replacement—or, in the case of some LED fixtures, hard-wired in place.
Lamp and lampshade made of Tiffany glass; c. 1890–1900; Budapest Museum of Applied Arts (Budapest, Hungary)
Lamp; 1902–1918; lead and glass; 67.9 x 52.1 cm; Metropolitan Museum of Art (New York City)
"Daffodil" lamp; 1904–1924; leaded opalescent glass and gilt bronze; height: 67.9 cm, diameter of shape: 51.4 cm; Metropolitan Museum of Art
Chandeliers in the Bibliothèque Mazarine (Paris)