How to tell the host not to play cards in the basement again?

Put up notices, property management office.

1. Post notices: You can post notices prohibiting playing cards in public areas of the community, such as elevators and corridors. The notice should clearly state that playing cards in the basement is prohibited, and inform the owner to transfer the card-playing activities to other suitable places.

2. Property management office: The property management office can take some measures to prohibit playing cards in the basement, such as posting notices at the entrance of the basement, or finding playing cards under the surveillance camera in the basement to stop it in time.