Found a picture of OP:

You might get away with it, but here’s the part that really sucks: you’d be stuck in the shed until they opened the next day. No riding a bike down the aisles, not even any trips to the bathroom. The alarm system likely has motion sensors, and the cops are called automatically when the alarm goes off.

Costco evening employee here:

Yeah, we check those at closing time. As well as behind the mattresses, the bathrooms and anywhere else someone might reasonably hide. There are generally people stocking stuff for 3-4 hours after the store closes and from 5 hours before the store opens in the morning.

There's a small window when the place is completely empty, but it's only from about midnight to 4am.

Just because the store closes doesn't necessarily mean it's empty, there's probably people restocking and cleaning in there

Not Costco but I walked into Walgreens last night about 10 minutes before close (paycheck didn't come through until fuckin' 9:45) to get some smokes and while I was standing at the register, they shut off the lights and only noticed me when someone came to lock the front door.

I get the feeling nobody is gonna be looking in the display shed for you. The only thing on their mind is closing out and going home. lol

You can get away with it if you cling to the ceiling Splinter Cell style when they check it for the night. Nobody looks up.

It's possible. It happened frequently enough at IKEA that it became an internet meme/challenge and they had to start prosecuting people who did it.

The general store employees have a big "not my job" attitude about it. If it's time to clock out, it's your problem that you're still in the store after closing. Not likely to confront you about it unless you are wandering the aisles.

Cleaning staff will probably tell someone if they find you hiding out.

Security guards will be actively looking for you and also search in obvious places like tents and sheds that are set up indoors, as well as behind shelving units, in the backrooms, etc.

Yes, they check that kind of thing

That thing is one bathroom away from becoming a 240,000 dollar tiny house

Check YT, Steve Wallis has probably already done it!

Challenge accepted!

Later:

24 HOUR OVERNIGHT CHALLENGE IN HOME DEPOT!!

"The store is now closed, please exit the building."

It's funny the amount of people thinking this is a hardware store, I would recognize those aisles and ceilings anywhere. That's a Costco (the particular style of price plate also gives it away)

I read a couple of very fun children's books based on that premise when I was a kid.

Apsolutly not 😁

My first stop after closing time would be the gigantic apple pie in the bakery section.

Likely not. If it weren't for the proximity sensors and contact sensors on the doors we'd never know when the mother-in-law escapes.