I once accidentally did this at a video store (when those were still a thing) and just kept recommending movies to people.
the manager gets a phone call like 
whatever you're doing at store 3901!!! keep it up!!! sensational!!!
I once wore a hertz polo and was able to get a free ride in the airport employee shuttle.
I had a red chef-coat for an old job, so you can imagine my experience when picking up my friends from their Target jobs.
Zellers in Canada which got bought out by Target and then run into the ground used to have restaurants in their general department stores. That was neat.
I swear that was a ucb bit.
A ton of people dressed like target employees or something then went into a target and ignored customers.
I can't tell you how many times people have assumed that I'm a worker at one of those big retail stores.
One I time I was actually at Best Buy with my headphones on and wearing a red shirt, and some dude still comes up to make me take off my headphones and is like "Hey, do you work here? Can you help me?" Motherfucker it's basic color theory, I do NOT work here.