Her work as a domestic violence therapist inspired Caroline to come up with the idea and since she put her post on Facebook on Friday, it has been shared more than 140,000 times, with many people taking up the goodwill knock-and-run themselves.

“Basically the concept of the ‘doorstep challenge’ is to reach out to those in our community who might be struggling at this time of year for one reason or another and spread a little Christmas cheer,” she explains to Mashable.

“There is something quite exciting about being an anonymous gift giver and I love the idea of giving with no expectations of anything in return,” she adds.

Caroline's full Facebook post:

The Christmas doorstep challenge is on! Imagine how many Christmases could be brightened by a simple gesture.
The rules:
1. Pick someone who has had a tough time or would simply benefit from some festive goodwill. It doesn't have to be someone you know well.
2. Choose them a gift - big or small.
3. Write them an anonymous note, some kind words about why you were thinking of them.
4. Leave it all at their doorstep.
5. Knock on the door and leg it - make sure they don't see you!
6. Feel happy knowing that you have spread some Christmas cheer with no expectations of anything in return.
This year I picked a single mum who lost her dad at Christmas last year and is putting on a brave face this year for her two young kids.
Let's share and see if this catches on and we can spread a bit of Christmas magic. Miracles really do happen!
‪#‎Christmas‬ ‪#‎Doorstepchallenge‬

Her actions echo the concept of this year's heartwarming Co-op Food Christmas ad, which sees a young man drop off a bag of Christmas shopping outside the door of an old man who's unable to get to the shops:

Her actions echo the concept of this year's heartwarming Co-op Food Christmas ad, which sees a young man drop off a bag of Christmas shopping outside the door of an old man who's unable to get to the shops:

How one woman's generous Christmas Doorstep Challenge is inspiring random acts of kindness