Would like to convert to tamper resistant receptacles to protect kids in house. Existing supply is 2 wire. Have been able to find only receptacles with ground. Can’t afford to rewire existing 2 wire knob & tube with 3 wire now. Would prefer not to tear up brick & plaster lath & floors to supply ground to each location (4 levels, 1920’s house).

Can I use the 3 hole TR receptacles? Would labeling them “No Ground” and / or blocking the ground connection to prohibit the use of a three prong plug be acceptable or advisable?

Thanks. Bob