With Christmas now fast approaching, households will be breaking out the old box of decorations including their trusty lights for the tree.
Some might notice that there's a single red light on each string which appears to be a spare, but it turns out the object actually activates a little-known setting.
The finding was shared by a woman who posts under the TikTok user @VizNelly who revealed what happens when you replace one of the light bulbs with the red spare.
As reported by the Mirror, the TikToker shared the now-viral clip, saying: "I was today years old when I found out what these are for." The user went on: "Remove regular bulb and replace."In the clip viewers can see them doing just that, then stepping back and waiting a few seconds before the lights begin to flash on and off.Adding the red light changes the lights' settings like a remote control would with a more modern set of lights.The clip left TikTok users stunned and amassed 19.4million views as well as over 6,000 comments from impressed viewers.One user said: "I thought they were spares."A second wrote: "Wait what???????
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