It is unlawful for any peddler or solicitor to ring the bell, or knock on the door or otherwise attempt to gain admittance for the purpose of peddling or soliciting at any residence or dwelling at which a sign bearing the words "No Peddlers or Solicitors" or words of similar import indicating that peddlers or solicitors are not wanted on said premises, is painted, affixed or otherwise exposed to public view; provided, that this Section shall not apply to any peddler or solicitor who rings the bell, knocks on the door or otherwise attempts to gain admittance to such residence or dwelling at the invitation or with the consent of the occupant thereof.