After the 7/25 hotfix, I can no longer build either heavi-watt wire behind ladders, and I can't connect to any of these wires either.
I can however, build a ladder on top of an existing wire.
If i queue up a build for both entities, it seems like the ladder will get built, and the wire will not.
It also looks like I can't build background blocks like tempshift plates or drywall behind ladders.
Build a Ladder Try to Build a Heavi-Watt wire on the same tile Be Sad