You realize this thing is just picking up radio waves?
You can adjust the sound levels and scan frequency, insuring that with enough fiddling you'll hear what you want to - but it won't be ghosts, just a
lack of understanding of technology and your imagination.
If you want to waste $80 on a "ghost box" go ahead - I'm going to buy an Easter Bunny Trap and some X-Ray glasses. Maybe we can meet up after and
compare our finds.
I have a friend who is an active ghost hunter with a fairly large organization. She takes audio recordings and reviews for ghost noises. I have
listened to quite a lot of audio with her, and where she hears a "ghost" I hear static and interference... You should buy a metal detector and at
least go out looking for something you can find. You might even find something valuable.
GHOST towns are a great place to go metal detecting. Picturesque, too.