Worked OK in Factorio 1.1
I looked in control.lua and I don't know how to fix it.

Found this in Factorio 2.0.7 changes:
-- Removed LuaEntity::neighbours support for electric poles and power switches.
-- Removed LuaEntity::connect_neighbour and LuaEntity::disconnect_neighbour.

Added post to this thread:
https://forums.factorio.com/viewtopic.php?f=6&t=91100

2.1.3: I've fixed it:
https://lua-api.factorio.com/latest/prototypes/ElectricPolePrototype.html#auto_connect_up_to_n_wires
Now prototype auto_connect_up_to_n_wires = 0, no control.lua is needed.

Thanks. The problem with setting auto_connect_up_to_n_wires to zero, is that one no longer sees the 'ghost' wire while placing the modded power poles. So how do I know when placing the modded power pole, how far I can place it. I think the auto_connect_up_to_n_wires should be set to 1, and control.lua should be fixed to work as before.