Also, check out
which might help if you have a Fannie Mae or Freddie Mac loan.
Whatever real estate agent or property preservation company was sent out by the lender should have left some type of notice at the house. Sometimes we are required to send certified mail if the notice we leave does not get us a response (I have to do this a lot with my bank-foreclosure clients). Sometimes a "cash for keys" offer will be extended to you, whereby you have a certain amount of time to remove your possessions and leave the house in "broom clean" condition with no damages to the home to get the check for your voluntary surrender of the premises.
A bank cannot usually lock you out of the house without following the eviction procedures your local justice of the peace or court system requires unless whoever was sent out deemed the property to be of less than usually $300-500 worth of value (amount determined by the lender/owner).
Good luck to you. I know this is a hard time, but you do have the right to redeem your CO property after the foreclosure sale... we don't have that here in Texas.
How long where you gone when the box was put on???
This is weird? I would suggest get in touch with the Public Trustee.
There is a usually a company which clears property of all items remaining you may have all ready lost anything left behind.
Sorry hear about this.
~ National Featured Realtor and Consultant, Lecturer regarding Credit Repair, Mortgage Loan Officer