Hiring a professional electrician to wire a house costs anywhere from $1,500 to $10,000 or more depending on the size and complexity of the project. Most professional electricians charge $50 to $100 per hour. While the extra expense is significant, it’s worth it to ensure the safety of your home’s electrical system. 

No, it is not safe to use an outlet that sparked. A spark from an outlet could indicate a short circuit, loose or frayed wiring, or other serious damage. Continuing to use an outlet that sparks can increase the risk of electrical shock, electrical fires, and other hazards. It's important to turn off the power to the outlet at the circuit breaker if possible and avoid using the outlet until a licensed electrician has inspected and repaired it.

If half of a string of Christmas lights is out, it is likely because of a single burned-out, loose, or broken bulb within that section. Long strands of lights often contain more than one circuit, so when one bulb fails, it can cause the entire circuit (or half the strand) to go dark. To fix this, inspect the unlit section and test each bulb to ensure it is tight and functioning properly. Replacing the faulty bulb or repairing a damaged shunt will typically solve the problem.

You can add an electrical outlet outside by sending a wire through the wall from an existing interior outlet. Without having to open up walls, you can thread a new electrical cable from the existing outlet through the wall and to the exterior. You’ll need to cut a hole in the siding to place your new outlet. Ensure that your outdoor outlet is a GFCI outlet (ground fault circuit interrupter outlet) per the National Electrical Code. It’s best to hire an electrician to add an outdoor outlet unless you have previous electrical experience.