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That Red-Tipped Bulb in Your Christmas Lights Has a Purpose

A collection of Christmas strand lights are tangled together.
Denise Cogliando/Shutterstock.com

If you get a real tree each year or decorate your home’s exterior, you might have seen a few red-tipped bulbs included alongside your strand of Christmas lights. You probably thought they were just spares, but it turns out, they have a much more interesting purpose.

Those red-tipped Christmas lights are called blinker bulbs or flasher bulbs, and they turn your strand of seemingly steady lights into a blinking, decorative masterpiece.

TikTok content creator @viznelly let the secret out, and it has since gone viral with multiple people shocked by the discovery (including myself). Essentially, all you need to do is replace one of the plain bulbs with one of the red-tipped bulbs. Wait a few moments, and boom! Your lights will start blinking.


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♬ It's Beginning To Look A Lot Like Christmas - Bing Crosby

The bulbs are different from the others in that they contain a bi-metallic strip inside. When the current hits the strip, it warms and lights up. Then, it cools down and goes out. This results in the blinking you see when it’s installed.

Prextex Christmas Lights

Grab this set of Christmas lights that come with flasher bulbs.

While your light pack should contain instructions on how to use these bulbs, you should install them at the base of your strand. The bi-metallic strip will only affect the lights that follow that bulb, so you want to place it near the bottom.

Whether you’ve already gotten your holiday decorations up or you’re waiting for Dec. 1, this handy little morsel of knowledge might just revolutionize your decor.

Shea Simmons Shea Simmons
Shea Simmons is the Editor In Chief of LifeSavvy. Previously, she worked as a freelance writer with a focus on beauty and lifestyle content. Her work has appeared in Bustle, Allure, and Hello Giggles. Read Full Bio »
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