I'm trying to add smart light switches (I was thinking of Shelly 2.5) to my appartment, but the problem is my lightswitch enclosure doesn't have neutral wires. It just has a live wire that enters the lightswitch, exits and goes on to the lightbulb. The lightbulb has a neutral wire which completes the circuit. This is standard electrical wiring over here in Eastern Europe.
I'd like to run a new conductor from the junction box to my lightswitch 1-1.5m through an existing kopex tube with 3 existing conductors.
Question is what's the best way to do this?
I tried stuffing the conductor down the kopex tube but it got stuck after about 15 cm. The tube diameter is larger than the wires, but perhaps they've bent and twisted inside.
Would an electrical fishing rod work for adding the wire without removing the existing wires? Thanks!