I know that all wiring methods that penetrate walls/ceilings must be approved wiring methods; How about on a custom made fixture where the transformers are in the attic and the secondary conductors that run from the transformer to the actual fixture head itself; yes it will pass thru grc thru the ceiling; but once in the open or not concealed portion; can I run single conductor? It is not going to be exposed to physical damage and will be out of sight for cosmetic reasons; any feed back is helpful, thanks