These stairs are made of scrap plywood I removed from the second shelf I disassembled to use as the second story of this dollhouse.  I needed one set of stairs to the attic room.  Most ways of making stairs are pretty complicated.  I think I came up with these after going through pics of interiors.  With the proper clamps and nailer, these can 

be made pretty easily.

This wood was already cut to this depth, I just needed to cut the width of the stair treads.  Obviously, these wouldn't function like real stairs, but they don't need to.  (A hand usually floats them up there anyways.)

 

At first glance they look pretty good, but as I was nailing them them they shifted a good bit off pattern.  I'll tell you how to do this without that happening.  I drew the treads profile and spacing onto paper (you want to roughly copy the pattern to use on the wall that you'll be nailing down also) then put them on their ends onto the pattern (I used scraps of extra wood as spacers in between). The wall that the stairs will be attached to should not be installed into the doll house yet>>> because I then laid the wall piece onto them.  I held the board in place while I was using a nailer to pop two nails into each tread throught the wall board (they had also been glued).

A better way would be to lay piece of rubber matting down (or some of that rubbershelf liner).  You need to do all this on a table or some other surface that can be used to clamp your project down onto.  Then lay down your stair template drawing (you need two drawings one for the treads to be placed on and one for the wall to assist with nail placement). 

Then set your treads on end, on the pattern, (the widths of treads should be cut as precisely as possible so that when clamped, every piece will be locked in, the rubber matting should also help tighten them down).  Use scraps as spacers between treads.  Put wood glue on the ends that are up and will be attached to the wall.  Then place the wall piece on top of your treads.  Get the other drawing, place it on the wall where you will be nailing the treads, make sure you match the drawing up with the treads on the opposite side.  Then clamp all that together with a large clamp.  Now you can carefully nail through the wall into your treads.

You could also (onto your uninstalled stair wall) place your treads on end with glue and clamp (to nail after the glue is set).

For the opening into the attic room, we used a 3 1/2"hole saw to drill two holes then connected them by sawing out the wood between them.

For me, typing all this out was more difficult than doing it.  It's much easier than it sounds.  I really like the looks of these stairs and it was a lot better than more difficult options.  I'm guessing you're here because you like to create and and if this all seems too tricky to you, try making something like the little dresser beside Barbie's bed.  I made that out of an Iphone box, check it out here.  Oh, and that pic above the stairs, I cut out of a box a Barbie came in.  It's a simple way to accesorize your doll house. You'll find lots of simple 

miniaturist tips on my site, I hope you enjoy them!

That 

  

Doll House Floating Stairs