i don't think switching it off for a day or two
will save any energy really.. you'll need to set it higher when you switch it back on, to make it cool enough for food.. and it is a health risk..
Keep your Fridge and Freezer full, and wrap up food and cover up any liquids. Not only will uncovered foods dry out and ruin the taste, but the moisture that is released causes the fridge's compressor to work harder. Make sure your fridge is in the coolest part of the kitchen away from direct sun and ovens or heaters etc. The ambient temeprature will make your fridge work harder to maintain the correct temp inside.