Advertisements were posted on the elevators and outside the walls of residential buildings, and the owners did not know. Which article of that law does this violate? How to implement sanctions?

The elevator and the external wall are of course the property of the owner.

The behavior of the property management company violates the provisions of Article 55 of the Regulations on Property Management: if it uses the parts and facilities of the property to operate, it shall go through the relevant procedures in accordance with the regulations after obtaining the consent of the relevant owners, owners' congress and property service enterprises. Accordingly, the realty service enterprise shall obtain the consent of the relevant owners and owners' congress when publishing business advertisements (which belong to the business operation behavior of the enterprise), and must obtain the advertising permission of the administrative department for industry and commerce before publishing advertisements.

Article 66 (1) (3) of the Property Management Regulations stipulates that, in violation of the provisions of these regulations, parts of the property or facilities and equipment are used for business without authorization, the real estate administrative department of the local people's government at or above the county level shall order it to make corrections within a time limit, give it a warning and impose a fine in accordance with the provisions of the second paragraph of this article; The proceeds will be used for the repair and maintenance of * * * parts and * * * facilities and equipment in the property management area, and the rest will be used according to the decision of the owners' meeting. The second paragraph stipulates that a unit that commits the acts listed in the preceding paragraph shall be fined between 50,000 yuan and 200,000 yuan. Accordingly, the owner can ask the real estate management department of the local government to punish the property company, and ask the property company to use the proceeds (including the use of the property owned by the owner for advertising, which should be paid to the owner without paying the money saved) for the maintenance of the facilities and equipment used by the owner, and the rest will be used according to the decision of the owners' meeting.