How can I serve someone when I cannot find them?

Usually, if you cannot find the person, you can serve them by publishing a notice in a newspaper, called service by publication. You can read about the requirements and steps in the “Service of Process” section of the Arizona Rules of Family Law Procedure. Your court might have forms and instructions for serving by publication.
•    Arizona Rules of Family Law Procedure
•    Maricopa County: How to Serve the Court Papers by Publication