Electrical junction boxes installed in walls and ceilings must always be ___.

Electrical junction boxes installed in walls and ceilings must always be accessible to ensure they can be maintained and inspected as needed. Accessibility is crucial for safety and functionality; it allows for easy access to the wiring connections inside the box, making it possible to troubleshoot any electrical issues or perform necessary repairs without having to damage the building structure.

While some boxes may be weatherproof depending on their location (for example, if they are installed outdoors), this is not a universal requirement for all junction boxes. Sealing may be important in certain applications to prevent moisture or dust ingress, but it does not apply to all situations and is not a requirement for all boxes within walls and ceilings. Additionally, junction boxes should not be hidden entirely; they must be located in areas where they can be accessed conveniently, especially since local codes typically mandate that they be within reach for maintenance and code compliance.