English: Main safety rule - remove the voltage before any action at electrical wiring. Especially actual for the DIY'ers. If you're doing some simple works, where you have enough skills, required tools and feel yourself sure to do it without specialist's help - don't ever forget about your own safety before starting any work. I can joke at people frightening them working under voltage, but I'm trained to do it for a long time through lot of shocks. So, don't risk to damage seriously your health or even die.

• Indirect illustration - servicing distribution board intime. It's age is about 25 years, so some circuit breakers may not work normally and cause the fire. But I've replaced old Soviet circuit breakers by new and put modern copper wires where gauge was not enough. But my neighbours still using outdated appliences risking to burn their apartments. So, take care about servicing of your distribution board approximately once a 5 years. If something is wrong there, ask the help from your energy company; replace group circuit breakers you can only after electricity meter if access is not sealed there and you're really sure what you do, at the slightest doubts or missing of the necessary tools ask help from qualified specialist. And one more time - don't forget to remove voltage before any actions.