How does the NEC address the modification of existing boxes?

The correct answer highlights that modifications to existing boxes must comply with current NEC standards and maintain installation safety. This is essential because the National Electrical Code is designed to ensure safety and efficiency in electrical installations. When existing electrical boxes are modified, it is crucial that any changes adhere to these current standards to prevent safety hazards, such as overloads, short circuits, or fire risks.

Maintaining installation safety involves making sure that any alterations do not compromise the structural integrity of the box or the circuit's operation. For example, if additional conductors are added, the box must still have adequate volume and be installed securely to counterbalance the change. Additionally, compliance with the NEC ensures that any modifications take into account enhancements in technology and safety practices that have evolved since the original installation.

To summarize, modifications that do not align with current NEC standards or that jeopardize safety can lead to serious consequences. Therefore, following NEC guidelines is paramount when making any adjustments to existing electrical boxes.