No ghost don’t have mouth and can’t really talk as they are disembodied entities that are dead. Some of them think that they are still alive and become Poltergeists here. Since the soul is energy you can pick up their EVP by using certain devices and even with you phone. Once the person dies they have a residual copy etheric clone soul body of their last life. Since some have died not long ago and they may think they still have a mouth and to them it may appear that they do so they try to speak but it comes out as Electro Magnetic Waves that some instruments can pick this up. You can communicate with them with recording devices If they still haven’t gone to the other side (their heaven).
You can operate programs to pick up Electronic Voice Phenomena through Electro Magnetic Waves through a Voice recorder or voice recorder function on phone. There are specific programs that are available that let you do this easily. While I don’t recommend to this, I have used one particular APP successfully to this on Google Playstore — Ghost Hunter – Detector Locator EMF EVP Recorder – Apps on Google Play
