Several signs may indicate outdated or unsafe electrical wiring. These include frequent tripping of circuit breakers, flickering or dimming lights, discolored outlets or switches, burning smells, buzzing sounds, or sparks. Hot outlets and loose connections are also warning signs. Additionally, using two-pronged outlets instead of three-pronged grounded outlets is outdated and potentially hazardous. If you notice any of these signs, a safety inspection is necessary to prevent electrical hazards.