If in the next couple of weeks a policeman comes to your door to request a "voluntary" search of the premises, you do not have to let him enter. Unless he has a search warrant, signed by a judge. Politely, respectfully, demand to see his warrant. If he does not have one, thank him and send him on his way.
If the policeman promises you "amnesty" for anything found in your home, he is LYING.
Again, you do not have to, and probably should not, allow a policeman to enter your home without a warrant, ever, unless you needed the policeman and called in the first place. If the circumstances are such that the policeman doesn't require a warrant to enter, you will know this because he will enter without knocking, with his gun drawn.
Hat tip: Hit & Run.