we have a rental mobile home, is a person under the age of 18 legally sign a lease agreement
Yes, under certain circumstances. A minor who is either married or a member of the United States military is an emancipated adult, and legally responsible for contracts/leases entered into for necissities. Additionally, a minor may file a petition with the court for a declaration of emancipation. Having such court documentation declaring the minor emancipated allows the minor to enter into binding agreements for necessities. A minor who is not emancipated, certainly may enter into a lease agreement, however, the lease agreement is voidable by the minor at any time, and the minor can hold the landlord liable under the lease, as it is not voidable by the landlord, on the basis it was entered into with a minor. In Pennsylvania, you must be older than 18 to sign a contract which is binding upon you. If you are younger than 18, the landlord may require a cosigner, such as your parent, who will accept legal responsibility for the obligations of the lease for you if you do not conply.