Weird wiring

A while back I did a quick inventory of the outlets in my house that needed a GFCI socket but didn't have one. A couple of outlets near bathroom sinks and one on the front of the house.

I started with an existing GFCI in the bathroom that had one because it had mysteriously tripped before so I didn't trust it.

So I pulled it and there was two sets of wires coming out of the load connection.

Let me take a step back. Generally a GFCI outlet protects itself and can also protect downstream outlets. I knew the other side of the sink was protected by this one, but there was another one too.

I replaced it and went to find the breaker for another one, the upstairs bathroom.

It was the same circuit as the first.

I checked the downstairs washroom and it too.

And the outlet on the porch.

And an outlet in the basement.

All of these were downstream of this one outlet.

My best guess is there was a short period of time when homes were built that the cost of a GFCI was more than the cost of labor and materials to wire things up in a weird way.

Before that time there wasn't regulations and it was far easier to just add a GFCI to replace a non-compliant outlet than major rewiring.

After that brief time it was cheaper to just slap in a GFCI as needed.

Just so crazy.