Don't know. The US hasn't annexed Canada yet. You might be hung from the neck until almost dead, then drawn and quartered, with the parts sent out to other municipalities as a warning to other would-be neighbor annoyers.
It's nice to see the quality of the responses on this site hasn't changed.
Peanutz, if Geekness is correct, and the potential penalties really exist for installing a backup alarm, I suggest your Uncle flee to the United States, and request Political Asylum. The same application would allow him to request protection under the Convention Against Torture (CAT).
I suspect Geekness was trying to rudely inform you that the senior members of this site have made a near-unanimous decision that the ambiguous question posed, "What is the name of your state (only U.S. law)?" does not mean that the question only need be answered if you are in the United States, but actually means "Don't ask questions about non-US law".
In any event, I suggest your uncle talk to whomever may be attempting to collect these "hidden fines that accumlated over time". Fines are generally assessed by the government, not by neighbours. I also doubt that his home is at risk over this.
It really sounds like the neighbour is a bully. I suggest ignoring him, and seeking competent legal advice. At a minimum, contact the city/town/village/whatever and see if you can find information about noise laws.