Any advise on pest repeller and how they work

I have an issue with mice that are not in my house but come to my property; I already have bait down done by a professional ; however I have purchased a sonic machine ( Pest stop pest repeller )from Adoric that has an electromagnetic signal that covers the house through the wiring system ; but what exactly does that mean? How does it work? does size matter in this instance as I have a small house but this machine can cover a large house?

Any advise on these machines and how they work and if so safely will be welcome; my worry is when it says it uses the house wiring; what exactly does that mean ?

Many thanks for any help with this