"How long does the foreclosure process take?" 

In Wisconsin, typically you are considered to be in default of your mortgage after falling 3 months behind, or not making a payment for 90 days.  At this time you will be sent a foreclosure warning letter and your lender will file a foreclosure lawsuit and the county sheriff will serve you with the papers.  This takes 30-60 days.

Now that you have been served the papers, the clock is ticking... You have 20 days to respond to the court (either "I paid", "I will pay", or "I don't owe it and why"), or the foreclosure judgement will be entered against you.

Once the judgement has been entered against you, there is a 6 month redemption period within which you can reclaim your house if you pay the past due amount plus any interest and fees. 

At the end of the redemption period, the sheriff's sale is scheduled.  This will takes another 4-8 weeks and must be published in a newspaper and public records.

Things can happen fast after the sheriff's sale.  Once the sale is confirmed, you will receive a notice to vacate the property within only a couple days.

Total time from the day you stop paying until the vacate date is approximately 11-13 months, or right around a year.

Check out my post 7 Solutions to Foreclosure for ideas on how to work through the foreclosure process... http://activerain.com/blogsview/246995/Falling-Behind-on-Your

The foreclosure process varies from state to state, and is a very complicated process.  If you are facing this situation, you must consult local legal, tax, and real estate professionals for advice on your individual situation.