u/Ascarmillion

So I'm making a castle, and I would like pillagers to spawn there naturally. I don't know how it works exactly, but in the pillager outpost, there is a bounding box, and pillagers spawn inside it, right? kinda how witch huts have one too for witches. Is it possible to create that bounding box with commands for pillagers? I would like it to have the same size as the Pillager Outpost