Never put a penny or other metal object behind or in place of a fuse. Before touching anything, make sure your hands and the floor are dry. If your breakers trip or your fuses blow repeatedly, call a licensed electrician, because this may indicate a problem in your electrical system. Some larger household appliances, such as washers, dryers, stoves, refrigerators, or air conditioners, draw more current and have their own circuits. A consumer must never plug in additional appliances with any of these products - doing so could create an overload condition.
Smoke detectors have a test button.
Pressing the button does not necessarily mean that the detector works. Often, it simply indicates that the battery in the detector works. To test a smoke detector, follow the manufacturer's instructions. The detector should be tested monthly and batteries replaced at least once a year, or when the battery's low warning sounds, whichever comes first. Some permanently wired smoke detectors have battery back-ups, in case of power outages.