What kind of wood/material for project?
magnets can always be defeated with enough pull. I can't tell how you want this setup? do you want it attached to the side of the fridge parallel to the floor at perhaps three feet off the ground? On second thought I think you want it against the side of the fridge. You really can't use hardware like screws to attach it to the metal of the fridge, unless you are very careful. Yes, you could drill 4 holes and use self-tapping screws, but you don't know what is on the other side of the sheet metal, your drill could hit something and damage it. You might be able to epoxy it, but that is kind of permanent. I'd try double sided tape. Find some that is rated heavy duty.