Ok in my home in markarth i set up orcish armor on the maniquen and i took it off to sell it, i made 2 sets, and it keeps appearing! i don't want it there! why?

armor maniquens are notorioussly buggy
try putting different armor on?
EDIT: to be clear put different armor on the maniquen

the glitch isn't associated with orcish armor, it's just the mannequins..they are all stupidly bugged. dude, i put daedric armor on mine once and left and when i came back, my mannequin was in the MIDDLE of my house in a location that it isn't supposed to be and it was naked, and my daedric armor was gone, nowhere to be found..the mannequin MOVED...on its own..

Or, you're not living alone in the house.

I've never used a mannequin, so I have no idea if they are buggy or not, but I believe others when they say it's buggy.

Maybe the mannequins aren't bugged. . . maybe you just ticked of a Daedric prince. I could totally see Sheogorath doing something like that, or maybe Sanguine.

It would be even freakier if you got up in the morning and it was stood at the foot of your bed. To be fair though thats the house I always use as it seems(to me at least) to be the least buggy. Oh and the dagger display case in the bedroom is dodgey as-well.

I did i put my ancient nord armor (i love that armor) and IT turned into the orcish armor!

It didn't turn into the orcish armour. If you check the mannequins inventory, your ancient Nord armour's still there. it's just that since you put on the orcish armour on the mannequin first, the mannequin glitches out and continually duplicates and equips the orcish armour, whilst retaining everything else you put on it afterwards in its inventory. it's a well known glitch, and you don't lose anything from it, it's just that you can't put any armour you want on display on that mannequin anymore as it will ONLY display the armour that you first gave it.

I've got invisible mannequin's in Riften. When they ARE visible, they tend to be randomly located throughout the basemant. When invisible, they are right where they're supposed to be, wearing what they're supposed to (at least when I click them, the amoror they should have is available for me to take).