So I created a few houses, some are upstairs that they're not on the ground. So I put wood platforms as stairs to let them go up. Soon a merchant moved. I can't seem to let it go upstairs to their room when night falls, but that's not the real problem, because after exploring a jungle, I went back to my house and found the NPC upstairs, but I don't know how to let it go down to the ground. Appearently I explored one more time but the NPC was still upstairs. I was also wondering how I could make the NPC go up and down the floors while I'm at the house with the NPCs' rooms. It seems that the merchant couldn't use the wood platform to go up to her room (but when I explored a random area and back, it was upstairs). But I was thinking of a way that my NPC could go back down to the ground WITHOUT having to explore somewhere else. Is there a way to let the NPC go back down? Are there any items I could craft? Are there like ladders in Terraria? Sorry if I don't have a screenshot but if you understand me please answer.
The NPC is not the Guide. It's a painter that sells painting materials.