Loooong time ago, in my teenage years as an apprentice electrician .. I spent a lot time in roof space of hospitals, large dept stores etc. Installing fire alarms and general electrical stuffs.

Of course I was very professional but one time, a colleague of mine was not so careful and managed to miss the kneeling board / joist and fell through the ceiling and right into the ladies shower room of a -- police station! Nobody was in the shower at the time but a few questions were asked!
Those were the days before camera phones so you were guilty of peeping if you had a red eye from the draught.