7 Holiday Lights Mistakes That Could Put Your Home (and Safety) at Risk

Running Lights Through Closed Windows or Doors

It may seem inconsequential (or even design-minded) to slip cords through a window crack or beneath a closed door to access outlets. But the pressure from the frame can pinch wiring, crack the insulation, and expose live electrical components. This creates a hidden short-circuit risk that can ignite nearby materials.

Keep exterior light routes clear and ensure that load-bearing materials do not compress any wires. You can also invest in weatherproof slim extension cords designed specifically for running under doors.

Connecting Old and New Light Strands

Exposure, storage conditions, and repeated seasonal use cause insulation to weaken and wires to fray. "One faulty wire or counterfeit plug can turn a quiet evening into a house fire within minutes," warns Hommer Zhao, a custom wire harness and cable assembly expert and CEO of Wiringo.

When you combine an older light strand with a newer one—especially a brighter LED set that draws a different unit of power—you risk overloading circuits and overheating plugs. If a strand looks worn, retire it. And always follow the connection guidelines printed on the box or cord tag.

Hanging With Metal Hooks or Staples

Reaching for that staple gun or a box of nails may seem like a simple hanging solution—but piercing a cord is also one of the quickest ways to create a fire risk. A tiny puncture can lead to arcing (when a current jumps through a sudden path in the air) or sparks.

Swap in plastic clips, rubberized hooks, or removable adhesive options designed for string lights and outdoor use. They'll help protect your wiring from punctures and your home from subtle dangers.

Skimping on Quality

Bargain holiday lights are tempting, especially when decorating an entire home or outdoor display. But counterfeit UL or ETL safety labels (which indicate the product has undergone standard safety tests) are common on ultra-cheap models, and the materials inside may not meet any recognized testing standards.

That’s exactly the source of many seasonal electrical fires, Zhao warns. “Many cheap or untested imports skip these quality checks,” he explains, “and that’s when a simple decoration can become a serious fire hazard.”

A good rule of thumb? If a deal seems too good to be true, take a moment to research it. “High-quality lighting products are built under strict manufacturing standards that regulate wire thickness, insulation, and heat resistance,” Zhao says. “These standards ensure cables can handle continuous use without overheating or short-circuiting. Purchase from reputable retailers or directly from manufacturers to ensure authenticity.

Using Indoor Lights Outdoors

This is one of the most common, easily avoidable mistakes. Indoor lights lack the waterproofing and insulation needed to handle the cold, snow, and wind. Even a single evening of exposure can damage them, increasing the risk of short circuits and electrical failure. Conversely, outdoor equipment may pull too much wattage.

Always use appropriate equipment for the setting. Outdoor-rated plugs and cords should stay outside and vice versa—so be sure to read packaging labels thoroughly.

Hiding Cords Under Rugs or Behind Furniture

Cords covered by rugs or wedged behind heavy furniture tend to overheat faster because air can’t circulate around them. They’re also more likely to fray without your noticing, especially if the area gets foot traffic.

Allow cords to breathe. Run them along the baseboard using proper cord covers to keep walkways clear while maintaining ventilation.

Overloading Indoor Outlets

“People often forget that even small decorations pull real electrical current,” Zhao says. When it comes to indoor décor displays that use electricity (think: plug-in garlands, animated displays, and tree lights), take care not to overload singular outlets. This can cause electrical components inside the wall to overheat silently—until you have a serious problem.

To avoid, never daisy-chain power strips. Instead, plug lights into multiple circuits and use a smart plug, timer, or surge protector designed to handle multiple items safely.