A lot of you might be comfortable tinkering with breadboards or Arduinos and hobbyist electronics, but mains electricity can be lethal. Please consider hiring a professional electrician before you start replacing failing components or power cables if you're unsure about what you're doing.
Stay safe :)
I did not listen to them, with the caveat that this anecdote is from 8 years ago, but it would have helped me if I had the capacity to accept their insights at the time.
In the United States (and other countries, but is it every country?) we can freely go into a supply store and purchase electrical components with no licensing or any other approvals. Simply go in, get what you think you need, and leave.
So when we were wrapping up the installation of our new kitchen some decade ago, I had recently completed a college Physics course, which I believe I had about a C- average in, and was very confident that I knew enough to wire the electrical connection on our steel range vent, with steel fume collection hood.
A year in, the little light bulbs that illuminate the range beneath had burned out from extreme heat. The metal base was still in the socket, but the glass was gone. "No problem, I'll turn the power off at the circuit and use a potato cut in half as a handle to force the base out".
Of course, a combination of shared neutral wiring, and my own errors, including that ground and neutral were 'the same' and I had tied the neutral into the hood, left me blown across the kitchen when I finally used the oven door handle with my other hand for leverage.
The headache lasted about a week. My chest felt like a couch full of old pennies. The first thing I remember was my wife sobbing, and the second thing I remember was that I am dumb and lucky. The third thing I remember was guilt for making my wife cry, and that's the one that finally registered within me that I should not be touching wires.
10 years later, I touch wires. I'm still not certified to do it, but there haven't been any more accidents. I will do only what I can convince myself I fully understand. Operations performed here are either very simple, or outsourced to professionals.
Hire an electrician.