Rating: Hard (it can be adapted to become easier)
For the main post about clue based traps. See this post.
This is a classic trap. Every cousin's family has had some variation of the Grinch stealing their Christmas, and they are sent on a hunt around to solve clues and find Christmas. Here is what we did one year.
My family was building a house that Christmas. The street names were the crossroads of that house. It should have been a quick trip there, but not knowing what was up my dad's sleeve, we proceeded with caution. The clue mentions elves on the lookout. We parked 1/4 miles from the house, and snuck up on it, so if there was someone on the outlook, we wouldn't be caught. Once at the house we found Clue 2 taped to the front door.
On the north side of the house we found the garage door opener. After opening the garage door, we found Clue 3 on the door leading into the house.
So we had to deactivate the alarm. I was almost 18 that year, and it was pretty obvious to me that those random numbers given in clue 2 had some sort of purpose. But to my 10 year old brother and 8 year old sister it wan't as obvious. At this age, I knew part of the fun of the trap was letting them figure things out too. After disarming the alarm, we went to the master bedroom thinking we were done only to find Clue 4 on the door.
And the final clue. 10 carolers were needed to break the trap and start Christmas. There were 6 of us. That meant we needed to find 4 more. Both sets of grandparents were in town that year - they would make up our final 4 carolers.
For another clue based trap, check out the Amazing Race post here.