Re: wall niches
Hi yes this works real good. Might i go so far as to say Custom... Damaging the plaster keying weakens the wall( the plaster globbies between the lath) remember plaster repair is not cheap. It helps if the walls are 2by6" for depth but 2 by 4" work. So you can install shelves or not and box the opening with drywall or plywood several finishes and trim or not depending on how you wish. In a narrow hall i would resist using trim an instead using drywall and corner bead and floating the wall so no outcrop. Have fun be sure not to cut threw wiring or plumbing - going slow with a small hole to observe whats in the wall and then enlarging it is playing it safe.
Any an all of my comments are just my opinion and not to be confused with facts.