Have you ever taken a look at the wiring of your home? For the majority of homeowners, the wires in the walls are a mystery, unless they have experience as an electrician. You might not be too concerned with your wiring until the time when you have a problem with it.
The reality is, though that there are many problems that could lurk just waiting for the right time and place to crop up. For example, if you have very old wiring in your home, it could be prone to overheating, shorts, and other issues. There are some types of wiring that were used in the past that no longer is used because of the fire risk, but if it is installed in your home and functioning properly, you would be none the wiser.
Whenever you are experiencing odd power fluctuations in your home, it might be worth checking with your neighbors if it is a problem with the power grid, or if there is something acting up in your home.