The police can search your home or your car if they get a warrant from a Judge or Justice of the peace authorizing this search. If the police ask you whether they can search your house or your car you should refuse until you get proper legal advice. If they assert that they have a warrant, make sure you see it and make sure it authorizes a search of your premises on the day they are searching. The legality of a search can be contested later, not while it is occurring. In some cases the police can search without a warrant.