The song the question is pointing to is “Leave a Light On” , which is sung by British singer‑songwriter Tom Walker.

Main answer

  • The track most people mean when they say “I will leave a light on” is Tom Walker’s 2017 single “Leave a Light On”.
  • The phrase “I will leave the light on” appears in the song’s lyrics and chorus, which is why many listeners remember it that way.

Extra context

  • Tom Walker is a Scottish-born, English-raised singer‑songwriter who broke through internationally with “Leave a Light On,” which charted in the UK and across Europe.
  • There are other songs titled “Leave a Light On” (for example by Belinda Carlisle), but the modern pop hit with the “I will leave the light on” hook is Tom Walker’s.

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