Knowing how much I hated the manager I worked with (and they did too), they had Jeff the tech guy from our data management department install a fake surveillance camera high on the wall behind my desk pointed down before I came in to work.
When I walked into my office, Jeff was naturally in the area talking with the gals waiting for me and they saw my reaction. They came over wondering what was going on. Jeff then said it was at the direction my manager that the camera be installed....... That even made me madder and after they stopped laughing, they explained that it was just a joke.
I was always playing tricks on these girls but that day they got me was for the history books..........