If you go to Tractor Supply, you will find the clear plastic covers that go on the inside of your glass or plexiglass. They have adhesive edges and when they get frosted, you tear them off and put on another. I just bought a pack of 5 for $10, I think.
I have an older Snap-On cabinet with a glass window and rubber gasket around it. I replaced that original piece of glass many years ago with a piece that lays over the opening with duct tape around the edges to keep it in place. The replacement glass is not the right size, but I use whatever I find and it is a lot cheaper then getting a piece cut to size with rounded corners. I put one of these clear tear offs inside.