The provisions of this Chapter are not applicable to alarm systems installed in Guam on the effective date of this Chapter or to modifications thereto, to audible alarms affixed to motor vehicles, to alarms installed on owner occupied dwellings, to alarm systems on premises belonging to the government of Guam, or any of its agencies or instrumentalities, or to a public utility whose only duty is to furnish telephone service pursuant to tariffs filed with the Public Utilities Commission.