You grab your toolkit from your desk and drive to The Department office. You park out the front and walk in confidently.
At reception you say "Hi, I'm here to look at the printer?"
The receptionist smiles at you and asks you to wait. She picks up the phone and makes a quick call. She listens, frowns, looks at you, says OK, OK a couple of times then hangs up.
She says "Someone came to fix the printer yesterday..."
Uh oh! Nearly busted! You apologise and make some excuses about this being your first day at a new job (which is true!). You walk out of the building quickly, leaving the receptionist smiling behind you.
Phew! Close call. You nearly got caught because the receptionist checked first before letting you wander around the building to do anything you wanted. Lets make a note that this is something The Dept got right (no hole here!)
Maybe try something else...
Note carefully: we always told the truth. We wanted to look at the printer (and some other things). We made no promise to fix it. If we had gained access, maybe the printer was a simple paper jam anyone could have fixed, including us.