The Auto-Enter enters data when a new record is created. On your radio button you need a script trigger OnObject Modified to perform a script.
I created a sample app. FM12
You will find a 'Case Statement' much easier to work with here than an If Statement.
There are major syntax problems in your original try at an auto-entered calcaultion.
Case ( Same as = "Home" ; Home Address 1 ;
Same as = "Work" ; Work Address 1 ;
Same as = "Church" ; Church Address 1 ;