What do you need to check before wiring a light switch?
Before wiring a light switch, shut off the breaker, confirm the power is dead with a non-contact tester, and look at what is already in the box. Note how many cables enter it, what type of switch is there and whether any wire is damaged or discolored.
Take a clear photo of the box before touching anything. It shows which cable came from where, and that picture is worth more than memory later.
Check the wire insulation too. Arizona attics and walls run hot for months, and old cable can turn brittle or crack at the stripped end. If the insulation flakes off in your fingers, the switch is not the real problem anymore.
Also look at the box itself. A metal box should be grounded, a plastic box should not be cracked, and the box should not be so crowded that the device has to be forced in. Cramped boxes make loose connections more likely, and loose connections are where heat starts.
What types of light switches are there?
Common light switches are single pole, three way, four way and dimmer types. A single pole switch controls a light from one spot. A three way pair controls it from two spots, and a four way adds a third. Each type has different terminals and cannot simply be swapped.
Buying the wrong type is the most common reason a new switch misbehaves. Look at the old switch: a single pole has two brass screws, while a three way has an extra dark screw.
Dimmers add another wrinkle. LED bulbs need a dimmer rated for them, otherwise you can get flicker, buzzing or a light that will not fully turn off.
Switch plates matter less than the device, but a hot or yellowed plate tells a story. Plastic that has darkened around the edges is a sign that current has been generating heat there for some time, and the cause should be found before anything new goes on the wall.
Why do some switch boxes have no neutral wire?
Many older switch boxes have no neutral wire because the switch only needed to interrupt power and never ran its own electronics. Smart switches and some dimmers do need a neutral, so those upgrades can mean running new wiring to the box.
Homes in Sun City and parts of Glendale built decades ago often use older wiring methods, and the box may show it. Finding no neutral is common and not a mistake by anyone.
If a smart switch calls for a neutral that is not there, that is a good point to hand the job over rather than improvise a connection.
If you do find a box with no neutral, do not borrow one from another cable in the wall unless you know exactly where it goes. Shared neutrals are a well known source of confusing faults, and they can leave a circuit energized when you thought you had turned it off.
When is a light switch not a DIY job?
A light switch stops being a DIY job when you find aluminum wiring, cloth covered cable, a warm or scorched box, or a circuit that trips. Those signs point to a wiring condition that a licensed electrician should inspect before any new switch goes in.
Stop right away if you smell burning, see sparking or find the switch plate hot to the touch. Those are not problems a new switch will fix.
Also leave it alone if you cannot tell which breaker feeds the box. Guessing at the breaker is how people get shocked on work they believed was dead.
Give yourself the best odds by writing down what you find and what the problem is, such as a light that flickers, a switch that crackles or a fixture that works from one switch only. That description helps a tradesperson fix the real cause on the first visit instead of the second.
What does a licensed electrician add to a switch swap?
A licensed electrician adds a trained check of the whole circuit, not only the switch. They confirm the box, the wire condition and the load are right, and make sure the work meets the rules that apply where you live in the West Valley.
Switch jobs are quick visits, which is why many homeowners hand them off. Vortech Air-Conditioning & Electrical, ROC 341933 for electrical work, serves Glendale, Peoria, Sun City, Sun City West and Surprise.
If you have several switches to replace, bundling them into one visit makes sense, and it is also a chance to have outlets and fixtures looked at.
A good visit also looks at what you did not ask about. While the plate is off, the electrician can see the condition of the wiring, the box fill and the way the circuit was originally put together, which are things that cannot be judged from the outside of the wall.
More questions: Rewiring, Outlets and Switches: 12 Most Asked Questions