Gambling or going on a game show both have to do with the spirit of greed. For that reason even a free lottery ticket is said to be wrong.
Awake 1994 August 8 p.15 Is Gambling for Christians?
What if a person is offered a free lottery ticket or free money to use for gambling? In either case, accepting such an offer would still be supporting a gambling operation—an operation out of harmony with godly principles.
The story of the person at work accepting a Christmas bonus reminds me of an experience i had. I was telling a couple of shop keepers the other day that this year was my first Christmas ever. They laughed, couldn't believe it, and asked why. I said i was raised a JW. She goes, "of course, my husband runs a company that has a JW. When the JW said he doesnt celebrate Christmas the boss said 'great, you can work on Christmas day' . The JW got all defensive and refused".