u/Ghost-Apple3555

We just bought our first house, and our home inspection noted that we have aluminum wiring and need to have CO/ALR-rated devices and AlumiConn or COPALUM connectors pigtailed at every connection point. Apparently, there are AFCI breakers already installed. I'm having an electrician come to look things over and give us a quote, but electrical is over my head with trying to understand it. Does anyone have some insight to share on A) how dangerous things are before we fix it and B) how involved will having someone fix it or c) what do all those acronyms mean in non-electeixal terms. Lol

Any advice would be appreciated before we jump into things. Thanks!