In Terraria, when a new NPC arrives, I see my friends NPC's to go inside like a charm. For me though, I have walked away from them, gone to the underworld away from them, done every little tip people have given me, but the NPC's NEVER spawn inside my house. I have to manually make a staircase for them to walk inside.Can someone help me?
I had trouble assigning rooms to NPCs too. It turned out to be because the house I was attempting to assign them was too close to some Corruption. Try getting rid of any Ebonstone or vile/corrupt grass you have nearby.
Also note that NPCs won't share a home with each other.
Thirdly note that the NPCs will "teleport" around if you leave the area for awhile and come back. This may be what you're looking for if you're having trouble leading them somewhere.
Go somewhere where you're not gonna see them, like mining, for a half an hour or so and they'll most likely be back in their rooms. And also try to designate rooms to the NPCs by going into the inventory and on the right side, beside your equipment etc, click on the little house and click on an NPC icon, and clicking on a room