Hanging up things in an office?

im a matinence man for my company, part of my duties is to hang thing up, i have been using a normal stud finder and self drilling metal screw to drill into the metal studs. today i sall a note from the leasing company saying that we should NOT do this and we have been drilling into electrical panels and other peoples suites! the drilling into others suites is BS, i have been using 2.5" screws but is this the other part a valid complaint, how can i tell if i am drilling into electrical panels, my stud finder dosent have a power detection icon, any tips on how to hang things up in the future?