Before
For god's sake, use a professional! We are in an old house and I literally am having a full modernization going on right now. Their work is pristine. I can hear them downstairs right now.
Even if your house was built before electricity was common, and over 100 years has passed, that is no excuse for crappy work. Like many others in this thread, I have a combo of hidden knob and tube, mixed with decades of home wiring. It's expensive to fix, but we are doing it. When they are done today, there will be no active, dangerous old wiring. And we will finally have enough outlets for modern living.
Edit: I just showed this to the master electrician down there and he was floored. Then he offered to do that too if I want lol. I said only if he can string the wire so it catches people's foreheads as they use the stairs.
After
For God's sake, use the expert! We were in the old house and now I have a complete complete modernization of their work basic
Even if your house was built more than 100 years before electricity became normal, it still does not forgive bad deeds. Like the rest of this thread, I also have buttons and tubes hidden in the house wire for decades. It is expensive to fix, but if they are made today we will, no active, dangerous old wire finally we have the appropriate results for modern life
Edit: I showed it to the electricians there, he was on the ground and I volunteered if I wanted to and he told me if he could tie the wire, so people would hold their foreheads when using the ladder.