To do this you have to be self employed.  If you are, and your wife actually did perform work for your business, you would be able to include your wife as a subcontractor and your wife would include the income on her return as self employed income.  If the amount is less than $3500 your wife could include it as casual income (other employment income).

You do need to be able to demonstrate that your spouse did indeed perform a duty for your business, and the compensation needs to be reasonable.  You can't claim paying her $50,000 for sweeping a home office once a week.

If the work performed is actually significant in time spent then you need to look into registering a payroll account and then deducting payroll deductions and remitting them on a regular basis.  

All this is moot if you are not self employed.