Ok here we go.. If it is a multi use commercial situation such as a strip mall, and you use romex to wire lets say a furniture store or shoe store, but nearby they put in a greasy spoon fast food counter, you could get some serious rat chew the romex up problems over time. I have seen just such a situation before firsthand. The application was a single story strip mall made with timber and had drop ceilings. the rats were able to get around the firewalls (mostly where trades did a lousy job of sealing). I found sections of very nicely completly stripped energized cable runing in metal studs behind sheetrock which was removed for remodel work. At least the guy who ran it used insulated bushings where he passed thru stud openings.
