A seguir, um trecho do National Electrical Code:
406.4(D)(2) Non–Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (D)(2)(b), or (D)(2)(c).
(a) A non–grounding-type receptacle(s) shall be permitted to be replaced with another non–grounding-type receptacle(s).
(b) A non–grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked “No Equipment Ground.” An equipment grounding con-ductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
(c) A non–grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked “GFCI Protected” and “No Equipment Ground.” An equipment grounding conductor shall not be connected between the grounding-type receptacles.
Além disso, desde 2011, é necessário que todos os receptáculos das unidades de habitação sejam resistentes à violação e que sejam necessárias substituições para aderir a isso.
Você também precisa verificar os códigos locais para ver se os receptáculos de substituição devem ser do tipo Arco de Falha de Arco. O NEC agora os exige na maior parte da casa, mas alguns estados e municípios optaram por não cumprir esse requisito.
Boa sorte!