Aluminum wiring

Problem with aluminum is that has different thermal expansion coefficient and connections on wall outlets can get loose over time causing exposed wire surface oxidation and sparking/overheating (aluminum oxide is isolator). There are special wall receptacles for aluminum wiring marked CO/ALR.

My version of 'the problem with aluminum wiring' is that it was being used with connectors designed for Copper. Than, some of the above referenced problems start to happen. If aluminum was used with connectors and outlets designed for it I still don't know if it was OK?
I'd tend to want to refit with copper and all new everything.

I'll bet that single crystal copper would sound better than silver. just kidding.

The major problem with Al wire is that the ends connected to the various boxes/outlets etc. corrode over time. Al corrosion/oxidation is not conductive whereas copper's is. That is why the house fires (in very new housing at the time too) occured and Al wiring was ultimately banned in many jurisdictions.