Avoid paper. At all costs. Even if it means scanning everything
Get some scales. Now, measure how much 700 sheets of paper weigh. That's quite a bit. Now put a lighter next to them. Let the flame touch the paper. Once the fire brigades are finished with your house, come back here and read the rest of this long chapter. Get some scales. Now, measure how much 500Mb weigh. That's hardly anything, especially if they are on a USB key. Now, put a lighter next to those 500Mb. It probably won't catch fire. The good news is that your house is safe.