What should I do if I receive someone else's green card in America?

In the United States, when you receive someone else's green card, you should give it to the owner of the green card or the police in time.

The American permanent resident card, also known as the green card, is an identity document used to prove that foreigners have the status of permanent residents in the United States. "Getting a green card" refers to the immigration process of becoming a permanent resident. The legal permanent residency of green card holders is an official immigration benefit, including conditional permission to stay in the United States and get a job. The holder must maintain his permanent resident status, and if he no longer meets certain conditions required by the status, the holder may lose his status.