I know nothing about the internals of 1950's Canadian houses! If you have more than one power ring in the houes (and you most likely do) then try powering the PC from a different ring - that will likely mean moving it tempoirarily to a different room.
Do you have a surge protector between the PC and the wall socket? If not then get one. I use a UPS to power my PC and monitor, partly because we do sometimes get power outages here in Greece, but also because it isolates the PC from noise on the mains power.