Which wiring method can necessitate the use of an electrical box?

The use of an electrical box is essential for various wiring methods to provide protection, support, and access to the electrical connections and devices. Non-metallic sheathed cable, conduit, or flexible cord are methods that often require an electrical box due to the need for a secure connection point for wiring and to house electrical devices like switches and outlets.

Non-metallic sheathed cable is commonly utilized in residential wiring, and an electrical box is needed to contain the splice junctions or connections between different cables. Conduit systems, including both metallic and non-metallic options, typically require an electrical box for transitions and terminations. Flexible cords also necessitate the use of boxes when connected to devices, adding safety and organization to the wiring system.

The other methods listed have more specific requirements or may not universally require an electrical box. For example, while conduit generally would require an electrical box for terminations or device connections, the options focusing solely on metallic conduit or flexible cords do not capture the broader applicability of non-metallic sheathed cable or conduit to various installation scenarios. Direct burial wiring, while commonly used, is designed for installation without a box, as it is directly buried in the ground without the need for protection in a box when installed per code.