I have plaster walls with lathe backing. In historic district so conduit that shows won't work, need to install new wiring and outlet boxes because upgrading service to today's standards and eliminating knob and tube wiring. Need help with installing wiring and boxes for outlets in the plaster walls, any tips other than tear up all the wall?

Is the house old enough that it used balloon framing? That is a single 2 X 4 running from foundation to attic. Have the outside walls had insulation added? When you said conduit, were you talking about the surface stuff commonly tacked up on the outside of the wall, or do you have to use it inside the wall? If you can use Romex or BX, it will be much easier to fish stuff up through the wall.

For outlet boxes, look at the old work boxes. The metal ones with the clip that expands behind the plaster when you tighten up a screw may wok better than the plastic ones that an ear fold out. You just cut a hole to fit, push the box in and tighten up the screws, and you have a solidly mounted box. Just buy lots of blades for your jigsaw. The plaster will dull them quickly.

Exposed conduit was used in some areas inside and outside and must be replaced with "unobtrusive" wiring methods. The idiots that installed it also cut holes in the mahoghany baseboards that have to be patched, my problem. We have found some wire mold that blends with the top of the baseboard and the boxes can be papered or painted over to blend better, but the walls have firebreaks in the exterior walls anyway, haven't researched the interior walls, so drilling through is a problem. The house is 40 feet tall, 2 stories and an attic with mansard roof, so everything is really a challenge. Thanks for your input so far.;)