Check your inbox.
You don't need to continue the lie, simply spin it in your favour. Your wife said that you had a job, so she entered this information on the form which you subsequently signed. The job turned out to be bogus, but you didn't know you should report this to CIC. Now your wife is trying to use this against you, so you feel obligated to come clean and let CIC know what really happened (i.e. you were promised a job that never panned out because your wife lied). So, in this scenario, your wife is the liar, not you.
If you have any evidence, keep it in a safe place and make copies.
Your wife is a fool if she thinks that she can threaten you with deportation. She is the guilty party, not you. Yes, you signed that form, but remember *wink*, you never imagined that she was lying about the job. You needn't let CIC know anything further, as it would be a case of your word against hers, unless there is evidence to support either parties claims. At the end of the day, I would contact her and let her know that she has committed fraud (or misrepresented), and that any action she takes will have direct blow back on her and her family. Tell her that you prefer to simply walk away and not have anything further to do with her. She is still bound by the undertaking she signed, but try not to rely on her for anything, take care of yourself (job, housing, etc).
If she doesn't see the reality, make it clear that you will get a lawyer to fight whatever action she thinks she can take. Be firm with her, but try not to let your emotions get the better of you.
I'm pretty sure she is just angry and everything she has said is a bluff...call her bluff!!
FS