Ghost boxes are neat and can produce some interesting results. Having the disembodied repeat words is one way to show interaction rather than random chance answers. If we ask for a name... We will get a name. This is because there are names being said over the radio all the time. So I suggest asking the disembodied to respond in this fashion... Have them repeat... This is and their name. Being polite will produce better results.

Here's an example of repeating words back to you.

http://prosinvestigations.com/ghost_box_recordings

Neat deal... Well, like I was saying you may be supprised as to what the voices will say and repeat when asked... Goes beyond chance.