I own a ranch home on Long Island that was built in 1958. Currently, all of the receptacles (outlets) are two-prong and have a LOT of paint on them. I am working on re-painting the interior, and would like to replace the outlets with 3-prong. It appears that the house was wired using a 2-wire system with soft, gray insulation (no sheathed electrical cable, no metal conduit or flex). From this, I would guese that there is no ground at the outlets or switches? I know from the multiple posts, that I cannot simply replace the outlets without producing a code violation, and more importantly, a fire hazard. My question is, is it possible to re-wire the house without removing/damaging the interior walls (wallboard)? All of the outlets are wired from the basement (unfinished), while all of the switches are wired from the attic (also unfinished). I intend on having an electrician do the work, unless it is easy enough for me to run the new wires, then let an electrician connect the new wiring to the box (200-amp service with new box) It is a 3 bedroom, 1.5 bath house with approx. 25 -30 outlets - any ideas of what an electrician might charge? Thank you in advance for all help.