Doppelgangers

Today my coworker called a bookstore and was greeted by a woman with a voice supposedly "identical" to mine. She said: "Thank you for calling Barnes and Noble, this is Lara, how may I help you?" I was put in mind of Spenser's "false Florimell," who, despite having hair made of golden wire and being animated by a demon-sprite, convinces everyone that she is Florimell herself. If the bookshop girl and I meet, one of us may disappear into thin air...