It is likely it is one of the phones in the day room at the Anderson Center. Patient's can call out on those lines, but other people can't call in. They have to call the nurses station then have their call transferred to the patient phones. So if you know anyone who was a patient at the Anderson Center, or had any other reason to be around the patient phones, that may be who called you.
St. John's Hospital in Anderson, Indiana now known as St. Vincent Anderson Regional. This is the outgoing number for ALL calls that go out through their switchboard system. This number does NOT work for incoming calls! You can not call it back!