The countdown to Christmas is well and truly on. 

With just a couple of days until the big celebration, many Brits will have finalised their festive decoration. But if you love jazzing up your lights, you might benefit from this little-known hack.

A particular TikTok user caused a stir online after revealing a tantalising tip about the often overlooked feature of red holiday lights.

The user, @viznelly, boasting an impressive 4,800 following amassed over the years, posted a video divulging…