['< sod > a double ceiling - mounted [ [ light fixture ] ] was installed in each room, usually controlled by a single [ [ switch ] ] mounted near a door. at most, one [ [ electrical outlet | electrical outlet ] ] was installed separately per room, since plug - connected appliances were expensive and uncommon. wiring was performed using type [ [ electrical _ wiring _ in _ north _ america # wiring _ log methods | 16th nm ] ]... nonmetallic [ [ wikt : sheathed | sheathed ] ] [ [ cable ] ], insulated with [ [ asbestos ] ] - reinforced [ [ rubber ] ] covered with [ [ jute ] ] and [ [ tar ] ]. < eod > < sod > a ceiling - mounted [ [ light fixture ] ] was installed in each room, usually controlled by a single [ [ switch ] ] mounted near a door. at most, one [ [ electrical outlet | outlet ] ] was installed per room, since plug - connected to appliances were expensive and uncommon. wiring was performed using roman type [ [ to electrical _ wiring _ in _ north _ america # wiring _ methods | nm ] ] ( nonmetallic ) [ [ → wikt : sheathed | sheathed ] ] [ [ cable ] ], insulated with [ [ asbestos ] ] - reinforced [ [ rubber ] ] covered with [ [ jute ] ] and [ [ tar ] ]. < eod >']