Confirmed that I have an egg eater. Possibly 2.

Not sure if it's my own fault. I had wired up a night light for them when I was having trouble getting them to go to bed a long time ago. It didn't really work.
I recently turned it back on and it looks like a few have been using it as a cue to go back into the coop and look for dinner before going back out into the pen before the door closes.
My 4 nesting boxes have had a golf ball and a ceramic egg in each since they went outside, and they hadn't been eating eggs for almost 18 months, but now it's become a pattern. I've caught them in the act a few times in the past week and even got a half eaten eggshell last night.
Commercial roller boxes are out of the question due to cost and space(I only have 9 laying hens).
Is there an alternative to freezer camp?