When examining the warrant, look for your name, your address, and a signature. This can help you decide whether or not the warrant is valid (true). The warrant will be in English. If you have trouble reading it or understanding it, get someone else in your house to help you read it or translate it, if possible.
If the warrant does not look valid, you should return it under the door and say it is incorrect. If the warrant the officer shows you looks valid, look to see if it was issued by a court or by ICE.
If a valid warrant was issued by a court and authorized a search of your house, you should let the officer in the house.