Working with high voltage house wiring can be extremely dangerous if proper safety precautions are not taken. As a homeowner, you should never attempt to work on high voltage wiring yourself unless you are a licensed electrician. However, if you do need to make minor repairs or replacements to things like switches, outlets, light fixtures, or ceiling fans, you can do so safely by following these guidelines.

Understanding Electrical Hazards

High voltage house wiring carries enough power to seriously injure or even kill you if mishandled. Here are some key hazards to be aware of:

• Electric shock - Coming into direct contact with live wires can result in severe shocks and burns. Even a minor shock can startle you and cause secondary injuries from falls.
• Electrocution - More severe electric shocks can lead to electrocution which can damage the heart and lungs or cause death.
• Arc flashes - Short circuits can create arc flashes which release intense heat energy and blinding light. These can cause severe burns.
• Fire - Faulty wiring is one of the leading causes of electrical fires in homes. Loose connections, damaged insulation, and overloaded circuits are some key risks.

So respect the dangers of working with high voltage wiring at all times. Even flipping a light switch on and off exposes you to some level of risk.

Working on the Power Supply

The power supply wiring includes the main service line coming into your home, the electrical panel/breaker box, and the large gauge wires distributing power throughout the house.

Never attempt DIY electrical work on the high voltage power supply. This includes things like:

• Replacing the main service line or meter box
• Upgrading the electrical panel or breaker box
• Changing the main shutoff switch
• Adding new high voltage wiring and breakers

This type of work should only be done by a licensed electrician due to the level of risk and electrical code compliance requirements.

Choosing Personal Protective Equipment

When working around exposed household wiring, proper PPE is essential for safety.

• Electrical gloves - Use rubber-insulated gloves rated for the voltages you are working with. They protect against electric shock.
• Eye protection - Wear safety glasses or goggles for protection from sparks and arc flashes.
• Clothing - No loose clothes or jewelry which could catch on wiring. Wear non-conductive shoes and long sleeve shirts.
• Insulated tools - Use tools with insulated grips and avoid working on live wires.
• Mat or shoes - Stand on a rubber mat or wear thick rubber soled shoes to avoid shocks.

Do not take shortcuts on PPE! It provides the only barrier between you and electrocution. Inspect it thoroughly before each use.

Turning Off Power and Verifying

Before doing any work on household wiring and devices, the first step is to turn off power to the circuit you will be working on.

• Find the circuit breaker powering the circuit in the breaker box and switch it to the "Off" position.
• Double check power is off by using a non-contact voltage tester. Check wires, connectors, and the device you will be working on.
• If needed, also turn off the main breaker or shutoff switch for maximum safety.
• Put tape over the breaker switch indicating it should not be turned back on during work.

Assume wires are live until you verify they are not. Accidental reactivation of a circuit can be deadly.

Following Safe Electrical Work Practices

With power confirmed off, use these safe practices when DIY electrical work:

• Work with one hand - Keep one hand in your pocket while using tools. This prevents electricity flowing across your chest if you contact a live wire.
• No wet conditions - Never work in damp areas or during storms. Use GFCI protected circuits in bathrooms and kitchens.
• Focus your attention - Avoid distractions which can lead to accidents around live parts.
• Clear access - Keep the work area free of obstructions for good visibility and mobility.
• Use insulated tools - Ensure your tools have properly insulated grips. Never use metallic tools which can contact multiple wires.
• Minimize exposure - Have wires disconnected for the minimum time possible and cap their ends.
• Double check connections - Tug test wires to confirm tight connections before restoring power.
• Keep others away - Prevent accidental reactivation or contact by others in the house.

Rushing increases risk. Work methodically and stop immediately if you suspect live power.

Restoring Power Safely

Once your electrical work is completed, you can safely restore power by:

• Inspecting the work area - Make sure no tools, wires, or conductive material got left behind.
• Re-confirming power is off - Check with a voltage tester before re-energization.
• Removing lockouts - Remove any breaker locks and "Do Not Operate" signs.
• Resetting breakers - With the area clear, turn the breakers back on starting farthest from the work area first.
• Testing operation - Have someone verify normal function while you stand clear of the equipment.

Follow safe electrical practices every time you work on household wiring. Pay close attention to hazards and don't take risky shortcuts. If uncertain about a project, hire a licensed electrician to ensure safety.