<P> In North American residential construction , aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices . Electrical devices ( outlets , switches , lighting , fans , etc . ) at the time were not designed with the particular properties of the aluminum wire being used in mind , and there were some issues related to the properties of the wire itself , making the installations with aluminum wire much more susceptible to problems . Revised manufacturing standards for both the wire and the devices were developed to reduce the problems . Existing homes with this older aluminum wiring used in branch circuits present a potential fire hazard . </P>
when did they stop using aluminum wiring in ontario
mid-1970s