We should have started another thread on this, but here goes ...
Copper and aluminum are not connected anywhere, they need separation in electrical.
Electrical connections need to be UL rated for that specific connection due to moisture which causes an electrolyte issue, they even make wire nuts for this problem. Water lines are separated by a 4 inch or larger piece of brass or a specific connector in plumbing.
It all depends on what you are trying to do, moisture is the culprit. Have you realized that new pressure treated lumber can no longer be used with aluminum because of the copper treatment which is now used .
That is "dissimilar metals" in some of the building arena.
Google it and you will learn more than you need.