I need to know if there is any article in the NEC related to wire mold being mechanically continuous. I only run low voltage audio and video wiring. There are cases where I install a Surface mounted box with a piece of molding going strait up for about 8 feet then run the wire exposed. This is in a Vaulted wood ceiling. There is no way to install mechanically continous molding. Is there anywhere in the NEC with these rules?