Songfacts®:

• This song finds Charlie Puth crooning about an attractive love interest. Though the girl is totally wrong for him, she's got him in "a tight grip." Every time Puth tries to walk away, he gets turned on by her, like a light switch.
• The song started out as a gloomy, slow ballad. In an interview with Audacy, Puth said it was originally about him wishing he could "turn his brain off" as easily as we turn lights off with a light switch. Sticking to the light switch motif, he twisted it round to a funky, uptempo track about "being turned on" by a hot girl.
• Puth wrote "Light Switch" with his regular writing partner J Kash, and with Jake Torrey (BTS' "The Truth Untold," Justin Bieber's "Off My Face").
• Puth is the lone credited producer. Puth first shared "Light Switch" on his TikTok on September 16, 2021, documenting him producing the song. The video went viral on the platform and he continued to tease the song in various TikTok videos throughout the rest of 2021. He eventually released it as the lead single from his third studio album, Charlie, on January 20, 2022.
• Christian Breslauer directed the music video, which begins with an out-of-shape Puth after a breakup. An aerobics instructor (Billy Blanks) gets him fitter and trimmer only for the singer to find his ex has a new, out-of-shape boyfriend. "The way the song came about was so unexpected, that I had to do a video that was also unexpected. I can't just look nice on camera and sing the song," Puth told Audacy. "It needs to be me getting in shape and becoming what I think is the best version of myself... unbeknownst to me that the version that I was before was just fine."