I recently moved into a rental that has aluminum wiring. My understanding is that the wiring itself isn't dangerous, it's just the interface between aluminum and copper where you have problems because of the different behavior of the materials.
We did lose an entire "circuit" once and from what I gathered the issue was caused by a failure of a single outlet, likely due to the aluminum wiring. I believe the fix was to add, in essence, a converter that safely goes from aluminum to copper so that you can install "normal" outlets. The electrician suggested doing this throughout the house, but of course the home owner declined.
I since had a switch in a bathroom break (it physically broke - nothing related to an electrical problem). I opened it up to see if I could replace it and found this:
AKA this is aluminum wiring going into what looks like an otherwise "standard" light switch. It appears to have some goopy stuff on it for reasons that I don't understand.
The property manager will probably just send out an electrician. Normally I'd do it myself because it will take an electrician a week to get out here (I've replaced outlets with copper wiring before), but with the unknowns introduced by the aluminum wiring I'm thinking of just leaving it to the professionals.
Is this safe and code compliant? Is it probably unsafe but grandfathered in (until it needs replacement)? Is there an easy way to make this safe while replacing the switch?