An outlet box or enclosure mounted on a surface must be:

For an outlet box or enclosure that is mounted on a surface, it is essential that it is rigidly and securely fastened. This requirement ensures that the box or enclosure remains stable and properly positioned throughout its use. A securely mounted outlet box provides safety by preventing it from detaching under normal conditions, which can lead to exposed wiring, electrical shorts, or potential fire hazards.

A rigid installation also allows for the safe connection of electrical devices, as it can withstand the weight and force applied when plugging or unplugging items. It is important to follow these guidelines for the installation of outlet boxes to ensure compliance with safety standards and the NEC, aiming to protect both the electrical system and the individuals using it.

Other mounting methods, such as loosely fastening, temporarily mounting, or making the installation removable, do not meet the safety and reliability standards intended by the NEC, which could lead to hazardous situations in everyday use.