Halle Berry -- Dear Auction House, That Junk Ain't Mine

Halle Berry pulled the plug on a Canadian auction billed as the sale of 400 items belonging to the actress ... because the stuff just ain't hers.

Halle's attorney fired off a cease and desist letter to The Montreal Auction House over the weekend ... informing them the items -- including a nail clipper, a hairbrush and an antique sofa -- were never owned or used by Halle.

The auction was scheduled to begin Monday, but the auctioneers immediately postponed ... once they discovered all the items really belonged to Halle's ex, Gabriel Aubry.

If you're interested in bidding on Gabriel's zebra skin rug ... the auction's been rescheduled for July 21.

Also, seek professional help.