On 03/10/2016 08:40 AM, Wade Garrett wrote:
1979-built house, two bathrooms sharing a common wall, one plain
electrical outlet in each bathroom. Both outlets are on the same
circuit; i.e., one circuit breaker kills them both.

I want to install GFCI protection. Do I need to install one in each
bathroom?

Or is the downstream one protected by its upstream brother? If yes, how
do I determine which one is first in the circuit?





GFCI outlets have "downstream" terminals. if you use them, the outlet
connected to it is protected as well.

Full instructions should be included in the box, when you make your purchase