I am with others - I've never seen any such sign (at any hotel/ motel in which I've stayed). In NC, private property owners have the right to ban guns - they actually do not have to post this. But, this does NOT carry the force of law. All they can do, if they find out that you have firearms on their property, is ask you to leave (or remove the firearms from the premises). If you refuse, they can have the police remove you as a trespasser - but that does NOT constitute a firearms violation - only a simple misdemeanor trespass charge. Obviously, if someone made an issue about it, it would be stupid to let it go that far - so the whole legal issue is easily avoided.
I don't think I've seen any business in NC with a "no guns" sign for many years - basically ever since CC became legal. Of course there are places illegal to carry here, just as in most/ all other states. It's stupid to tempt fate by carrying in such places - and I never do that. But, if carrying concealed, just don't advertise it and it likely never will become an issue (for places in which it is legal to carry, whether or not the owner cares).