The voltage on an electrical outlet fluctuates constantly and is a "very correct, in the standard of safety and optimum" up to 253 volts for the top, and 215 for bass. In addition, secure your sensitive equipment such as modems and decoders for example ...
Electrical parts are normed 230V-50hz today. If you have any bulbs that burn out abnormally, they no longer support the current network standard (often stamped 220V).