Wires lay in wait inside walls for decades and unless the fuse blows or the circuits break, nobody considers the vintage of wires.
And, like many construction components, electrical service has a vintage.
Builders in the 1970s used aluminum wire, which ultimately proved to be sub par and unsafe, implicated in many fires.
Unfortunately, not all aluminum wiring has been remediated.
If your property was built in or had a major renovation in the 1970s, check for aluminum wires. Pull a cover plate off a wall socket or light switch and check.
Overloaded circuits cause fires. Open your breaker box and feel the breakers. If they are warm to the touch, the circuit is under stress and should be evaluated by a professional electrician.
Change any fuse panel to circuit breakers.
Wiring and cords are factors in half the electrical fires. Check cords for wear and tear of insulation. Do not run cords under rugs; they will abrade and become an ignition source.
Do not use extension cords as a permanent solution to provide electricity to an area or machine. These overload circuits by providing increased demand (electricity must travel extra distance and heat the cord) and extra outlets for plug-ins. Install new wall outlets if needed.
When using extension cords for temporary applications, use grounded plugs. If the cord has any nicks, cuts or is missing the ground prong, discard the cord and replace it with new.
Cut power to outside outlets at the circuit breaker box when maintaining lighting. This specific warning about lighting: just because the light isn't shining does not mean electricity is not flowing.
A few years ago, an electrician, well-trained with much experience, was electrocuted when the outdoor light timer sent electricity through a line he was splicing while standing on damp soil.
Know the current is off and inaccessible to the circuit on which you're working. Avoid electrocution by turning off the electricity. Tag out that circuit. Use cutoffs as close to the worksite as possible. And, never work on electrical circuits on wet floors or grass.