Thanks for the replies everyone. I ended up making one that is working great.
I had large plastic bucket that was about four inches larger in diameter than my kettle. I cut most of it off, so it is basically a one inch tall bucket. I then put it on my kettle upside down, so the sides of it are facing down. I also cut out an area for my chiller. Because the cover is larger than my kettle, even with a small cut out area for my chiller, nothing can fall in the wort.
Thanks again for all the advice