A cubicle or switching cubicle comprises some support and retaining rail or other projecting from its bottom wall (11) to accommodate arbitrary apparatuses (15). It comprises at least one positioning shoulder itself projecting from any of its walls for interaction in shoulder at one of the apparatuses concerned. The shoulder extends near the support rail and can be separated. It projects from the bottom wall. It appears in the form of a tongue or a plate which extends vertically to the bottom wall. The cubicle also comprises an accommodation opening (25) assigned to the positioning shoulder which extends like this near the support rail and is suitable to accommodate this shoulder as soon as it is separated from the wall from which it projects.
