guardianship is a legal relationship in which an adult is responsible for the care and decision-making of someone who cannot care for himself. the specific wording you use in your affidavit will vary depending upon your situation and jurisdiction. an affidavit is a signed, sworn document containing facts to which the affiant can competently testify. the affidavit should be filed in the court that handles guardianship and family law in the county where the person in need of a guardian resides or, if there are already court proceedings, in the court where those proceedings are taking place. then state your name and number the paragraphs, with each paragraph containing a factual claim. have the affidavit notarized and sign the affidavit in front of a notary. explain how long you have been treating the person, behaviors you have witnessed and recommendations you have given the patient.