A lot, that's why you'd have to trust them. I didn't say hire a homeless person.

As for fraud: not really. I book rooms for my spouse when she travels, and put her on as my guest. She travels, checks in, stays, and IHG approves it. They are the folks that told me to do it.
I see no difference in doing that, than booking and paying for a room for your best man to stay at during a wedding, your Aunt/Uncle during a funeral, your best friend when they visit town, etc..

How is it fraud? You paid for the room, the guest you specifically allowed to stay there stayed there... Who was damaged?