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As Willy Wonka says, I know a worse one. I did a "historic" courthouse that had a bell/clock tower. Did a bunch of work but had to backlight the clocks in the tower. The attic was infested with bats, there was so much guano that the ceilings were trying to fall. They literally hauled it out in dump truck loads. No one had been the attic in years, it took 2 people to push the attic panel out. When they did, it was like sands through the hourglass pouring through the hole.
Between that and fighting the bats it was pretty bad.

I rewired a wastewater treatment plant, which was probably worse, but way too much nasty for a comment post... On both of those, we would have to decontaminate, shower and change before going home, which I guess was ok, getting paid to take a shower...