Should I call the police when the property knocks at midnight?

If the property is legal and needs to be negotiated with you, then it is best for both parties to negotiate. If the other party is deliberately harassing, then you can call the police.

Legal basis:

People's Republic of China (PRC) Law on Prevention and Control of Environmental Noise Pollution Article 24 Industrial enterprises that use fixed equipment in industrial production to cause environmental noise pollution must, in accordance with the regulations of the competent department of ecological environment of the State Council, report to the competent department of ecological environment of the local people's government at or above the county level the type and quantity of equipment that causes environmental noise pollution, the noise value discharged under normal working conditions and the facilities for prevention and control of environmental noise pollution, and provide technical data for prevention and control of environmental noise pollution. If there are significant changes in the type, quantity, noise value and prevention and control facilities of equipment that cause environmental noise pollution, it must be declared in time and appropriate prevention and control measures must be taken.