I wouldn't say that there is any way to make an object literally catch on fire via magic. Or a person that touches said object.
I personally think it would be easier to cast at the person directly, so that whenever they do steal, something bad happens. If you don't know the person who is doing it, I would make something like a spell tag and place it among the objects that you desire to guard. And amulet, or even just some dried herbs or stones would work.