Several signs can indicate a light switch is bad. If the switch feels loose, slides down after you flip it, or requires multiple flicks to turn the light on, it may be failing. Other common indicators include flickering lights or a general failure to turn the light on or off. Pay attention to any unusual sounds, such as crackling, buzzing, or popping when you operate the switch. More serious signs, which can present a fire or shock hazard, include the switch feeling excessively warm or hot, sparking, smoking, or emitting a burning smell. If you notice any of these dangerous signs, stop using the switch immediately and call an electrician.

Yes, you can put a GFCI outlet in almost any electrical outlet location. As long as the outlet is wired correctly back to a circuit breaker, you can likely replace the existing outlet with a GFCI outlet.

The copper wire used in knob and tube wiring systems can last up to 100 years. However, it’s considered a dangerous and outdated wiring method because the cloth, fabric, or rubber insulation sheathing can become brittle and fall apart. Knob and tube wiring systems should be inspected if you’re considering buying a home with this type of wiring, or if you have problems with frequently tripping breakers, a sign that you may need to replace them.

When combined with a substantial solar system, if you have enough Powerwalls, you could go off-grid and be energy independent. But remember, you'd need enough Powerwalls to power your whole home continuously because a single Powerwall can’t power large appliances for extended periods. One Powerwall is able to power an average-sized home's emergency circuits, lights, and outlets. To power large appliances, you likely need two or three Powerwalls.