You may want to look at the article "Projections and Intersections: Paranoid Textuality in Sorry, Wrong Number" by David Crane (see the link below). Crane writes about what he refers to as "paranoid textuality" in the play; this phrase refers to a kind of paranoia that becomes an element in and of itself in the drama and that moves the action of the drama along. In paranoid texts, Crane notes, paranoia always becomes a reality.
Crane writes that the paranoia in this play is essential to the narrative; the telephone is the device through which this paranoia and its attendant anxiety are transmitted. The phone in this play becomes a portent of evil that is about to arrive. The play turns what is generally a comforting device that connects people to others into something that only transmits worry and eventually death. Rather than connect people, the phone strands them and subjects them to their worst nightmares.
This article is one place you can start your process of research and writing.