Night lights are small sources of light intended to remain on during the night or in dark places, either to help people see their way or to comfort those who may have a fear of the dark. Night lights are usually electric, either mounted directly in a wall socket or plugged in, but candle and oil night lights are not unheard of. One factor in choosing the night lights that are right for you is how bright you want them to be and how important energy efficiency is to you. Aside from the light source itself, many night lights have photosensitive triggers which automatically turn the light off if there is an ambient source of light, saving energy during the day and when larger overhead lights are turned on.
The most common night lights use a traditional incandescent bulb. An incandescent bulb uses a normal wire filament to produce light, and is not particularly energy efficient. Most incandescent night lights are in the 5 to 10 watt range. At a similar energy expenditure, but with a greater light output, are fluorescent night lights, which use approximately 7 watts of power.
Neon night lights offer a more energy efficient option, with most using around 1 watt of power. A neon light contains a small amount of neon gas, which lights up as electricity passes through it. Neon night lights are considered by many to be the ideal mix of light emission and energy efficiency. The most energy efficient night lights available are simple outlet-mounted strips which contain an electroluminescent surface. These night lights emit very little light -- they are often perceived as a slight glow, as of glow-in-the-dark paint or stickers -- but in exchange they use a negligible amount of energy, at less than .07 watts.
Incandescent and fluorescent night lights are a known safety hazard, with a number of fires started each year by combustible materials such as toilet paper, pillow cases and shirts being left to fall onto the bulb. For this reason, many safety experts recommend low-power night lights such as neon or electroluminescent models. With small children especially, electroluminescent night lights have the benefit of being cool to the touch, preventing any accidentally burned fingers.
Some light bulb manufacturers also sell bulbs with two modes. In their first power mode, they act as a standard 60-watt light bulb, emitting enough light to illuminate a room. In their second power mode, which can be reached either by flipping the switch twice or by waiting twenty minutes, the bulb automatically dims to be a 7-watt light bulb -- ideal for a night light.
Pricing on night lights ranges widely, depending on whether they are simply a light source and basic fixture, or whether they feature some sort of stylized design, such as a cartoon character or shell-adorned fixture. A simple wall-plug night light costs about US$10, while more advanced bulbs can cost US$20-US$40, and artisan night lights can cost hundreds of dollars.