You're opening yourself up to a world of pain if you facilitate this.
From a practical point of view, will a WiFi connection work reliably? Do you want to get into messing with repeaters? Are you prepared to be there to answer the calls when it's not working for whatever reason?
From a security perspective, once you give out your password, it's gone, out of your control until such time as you change it. You are then effectively giving anyone who wants it free access to your network and everything attached to it.