Has anyone ever done this before? Like, create a security guard sim, build a museum (or bank) lot, add a 'anyone fight burglars' mod, and then wait for a burglar to show up. I'm considering creating a bank, placing bags of money and gold bars in my bank, raising their value, and waiting to see if a burglar shows up to steal them.

I wonder if burglars can rob owned businesses.

Unmodded, burglars only come when everyone is asleep, and Sims can't sleep on community lots.

Though if you summon one with the Instant Inviter, they can take merchandise.

When I was playing the Caliente sisters, a burglar came when they were having an unofficial house-warming party and the house was full of guests, most of them very much awake. (By "unofficial" I mean it wasn't a "party" thrown through the game mechanics, but merely that they'd invited a lot of guests.) But I suppose that's a scripted event, so I suppose it's different. Also, since I knew the burglar was scripted to come, I made sure they had a burglar alarm!

As for burglars on community lots, I quite often see one walking by, but I've never seen them try to steal anything.

But OP was acting about burglars stealing from residential businesses, and, as far as I know, there's nothing to stop burglars raiding a home business when everyone is asleep. I've not actually seen it, but I don't play many home businesses. What's more, when I do play them, the owners very often only use them as a first step towards setting up a community lot business. i.e. When they have enough money to buy premises, they buy a community lot and move the business equipment there, and close down the home business. So as I say, I've never actually seen a burglary at a home business, but I reckon it must be possible. In our Veronaville, Juliette Capp is thinking of opening Capp Manor to the public as a way of raising some cash, which would be very welcome now that Consort (who owns a gold mine!) has moved out. Now I would imagine that Capp Manor, with all the expensive stuff that's there, would be a very attractive target to the criminally inclined. So I'll be strongly advising Juliette (and Hermia who lives with her) to make sure their security is good,

My residential police station got burgled twice.