Santa's key

Santa mailed us this special key a few years ago and each year we attach to our door on Christmas Eve, with a note that reads something like this:

We don't have a chimney for you to climb through,

But if you don't visit our house we don't know what we'll do.
Some say you are magic and can use any old key

As long as we hang it out in a place you're sure to see.
So we're leaving this old key right outside our door

Saying our prayers, jumping in bed, and we won't worry anymore.