The few Mennonites I've known have all had phones, electric lights, fridges, stoves, etc. The basic, functional stuff. One guy even kept an old laptop for doing his books.

The way it was explained to me is that modern stuff that's used to a 'good' purpose like phones for urgent communication and business, or electric refrigeration to keep food from spoiling are okay; but things meant to entertain or replace "the work of human hands" is not.