According to 314.23, how must a device box be mounted for support?

The correct method for mounting a device box for support, as specified in Section 314.23 of the NEC, is with two nails from the back or ends of the box. This requirement ensures that the device box is properly secured to the structural framing, which is crucial for maintaining the integrity and safety of the electrical installation.

Using two nails provides a stable support that helps prevent the box from shifting or becoming loose over time, which could lead to issues such as wire strain, improper device installation, or even electrical faults. This mounting method complies with code requirements, emphasizing safety and reliability in electrical systems.

While other methods of support might be possible, they do not meet the code standards for ensuring adequate strength and stability in the installation of electrical boxes.