You can take a few steps to prolong the life of your holiday lights. Make sure to replace burnt-out bulbs as quickly as possible to avoid overloading the rest of the circuit and knocking out more lights. Before packing them up each year, plug each strand into the wall to confirm everything is still working. Wrap the lights carefully back into their original packaging or something similar—winding a strand tightly together or leaving it to hang loose in a storage bin can lead to frayed or damaged wiring. 

The cost to repair a short circuit depends on the type of repair. A faulty outlet or simple loose wire can be a simple fix that might only cost a handful of dollars. For example, if you need to rewire a house, you’ll spend around $2 to $4 per square foot, but replacing an entire electrical panel costs anywhere from $500 to $2,100.  

Yes, outdoor lights and receptacles should be on a ground-fault circuit interrupter (GFCI) for safety. The outdoors is considered a wet location where GFCI protection is generally required. A GFCI enhances safety by automatically tripping and shutting off the circuit if it detects an imbalance, which protects against electrocution and reduces the risk of an electrical fire. While it is the safest approach for all outdoor electrical components, specific requirements can vary depending on the type of light (e.g., pool lights), its location, and local electrical codes. For guidance tailored to your specific situation, it's best to consult a professional electrician.

If you need to visually inspect your Christmas lights to determine which are good and which need replacement, there are a few things to look for. First, look for discoloration, such as a dark spot or two on the inside of the glass. The spot is an indication of a burnt filament. Also, look for missing filaments, cracked bulb glass, and broken sockets.