Probably not what you're thinking about specifically, but for many years in the 1990s I did VO work for an east coast company that would produce generic commercials that covered specific retail categories.
I believe they had a couple of dozen "lines" of commercials like this. (Mens and women clothing, jewelry stores, Home Furnishings, etc.)
I did dozens upon dozens of Mens Clothing store customization VO tags for them over quite a few years. The local retailer would use the packaged spot and simply affix their location brand info on a graphic custom end slate with my VO to make it seem like a spot for a local firm.
They had sales teams across the country, so the viewers in Nashville were seeing the same spot as the viewers in Denver, but for different local firms.
That was pretty common in the early days of TV when quality production was costly.