This is smaller than normal door because it is a door in the back of the stairs, but you can use this same idea for your own handmade interior doors throughout your dollhouse.
If you will be opening and closing the doors a lot then I would recommend something more durable than card stock.
Cut a piece of 24 gauge wire to the height you want your hinge to be.
Cut a horizontal piece of card stock at the same height and about 1 inch wide.
Use a toothpick to put wood glue in the center of the card stock piece.
Use your tweezers to drop the piece of wire onto the wood glue.
Press it down with the tweezers.
Use your toothpick to put a tiny bit of glue on each side of the wire.
Fold the piece of card stock over the wire and use your tweezers to pinch in close to the wire to get the paper secure around the wire.
Quickly open the paper back up and press flat on a surface and be sure the paper is straight. Don’t wait too long or the paper will be glued together.
Let this completely dry
Determine the thickness of your door and cut the hinge to that width.
Paint your hinge front and back the color you would like it to be.
(I choose to paint mine shown here after I had glued it to the door.)
Glue one side of each hinge to the door where you want the hinges to be
Keep the hinges open so that the glue doesn't seep through the paper.
Once they have dried put glue on the other side of the hinges and glue that to the inside of your doorway.
Brace with paper shims if needed until it is dry.
The card stock will be pretty durable, but you can also paint the paper with Modge Podge to add some strength.