"could you set and alarm on the phone to go off? or could it be opened to the part where you set the volume/ choose the ring tone and have the actor select it? orrr could you have the phone not ring on stage, but have someone back stage with a…"

"I did a production of Dead Man's Cell Phone - where the cell phone was constantly ringing. For that show we built a custom cell phone using the shell of a fake demo cell phone you would usually find on display in a store. We used an Arduino…"

"Call the props shops. There are dummy phones that ring when triggered from an offstage transmitter."

"I've done this before and it was a huge pain in the butt, but then I learned about the phone box (a small speaker you can attach somewhere). You could use the alarm clock function on the phone, though that might be risky because…"