I have a RuleTile with a bunch of rules. I created a prefab of one of the sprites. I attached that prefab to the appropriate rule. I drew a little room with the RuleTile, and there was one use of the sprite that had the prefab. When I run my game, no GameObject is spawned. In case it's relevant, the GameObject prefab I wanted to use for the rule has a collider and a rigidbody.
I have a RuleTile with a bunch of rules. I created a prefab of one of the sprites. I attached that prefab to the appropriate rule. I drew a little room with the RuleTile, and there was one use of the sprite that had the prefab. When I run my game, no GameObject is spawned. In case it's relevant, the GameObject prefab I wanted to use for the rule has a collider and a rigidbody.