Here are a few suggestions
1. Get a large Christmas tree and invite interested individuals to decorate it . If you have larger space and bigger teams there can be a Christmas tree decoration competition between the teams.
2. Invite a carol singing group from a local church to sing one evening at the office. Alternatively organize a carol singing competition among various teams. You can also explore the possibility of getting someone to train the employees to sing and having an evening of carols inhouse.
3. You can also organise a Santa Claus ( if possible an employee dressed as Santa) and have a variety of gifts that can be distributed by Santa maybe as a lucky draw using employee code or as spot prizes that you can decide on.
4. Having a dress color scheme for work on the 24th should also be explored.
Build up on the above ideas and I am sure you can even more unique activities to make the Christmas week fun and also ensure a healthy engagement with the employees.
11th December 2015 From India, Mumbai