Different Electrical Box Sizes and Shapes help your right choice

The shape of an electrical box can help you identify its purpose. Different electrical box sizes fit varying installation needs.

A standard rectangular shape is the most common electrical box. It houses a single electrical switch or outlet and comes in metal or nonmetallic units. These boxes protect wiring from the elements with gaskets, sealed seams and watertight covers.

A square electrical box, also known as a “double-gang box,” houses two devices. They'll have a combination outlet/switch or a pair of outlets/switches inside.

The round or octagonal box houses lightweight fixtures or safety devices in the ceiling. These are used for lights or smoke and carbon monoxide alarms.

A ceiling box is for heavier fixtures, such as ceiling fans or chandeliers. Be sure to choose a ceiling box that is made to support extra weight.