The fourth amendment gives people the right to secure their property, papers, house, against unreasonable searches and seizures. The police cannot search the people's property unless they have warrant.
I have never been in a real life example of this but I do have idea on how something like this can take place in a real life situation. Let's say the cops see a man walking around with his hoodie on looking really suspicious he's looking around him as if he's hiding something. Right away the cop has a suspicion about the man. So the cop follows the man and he ends up at the mans house. Of course a cop would say something like "Open up its the police we need to search this house!!" Or something similar to that. But according to amendment IV a police officer can't just search your or a persons property unless he has a warrant. I think that would be a real situation that would take place