Long distance

How can I control a smart device over a distance of 150m? I have a horse stable 150m away from the Homey and would like to control the smart leds.

What protocol are the smart LEDs? If WiFi then should be easy enough

You need to add routers between the Homey and the lamps.
Everything not on battery will route/mesh, just be sure what protocol your lamps use (WiFi, z-wave, zigbee).

Good idea. I will use.a Powerline adaptor to bridge to the stables 150 meter away and then use wifi connected led lamps to switch them.

Why not just run a length of Cat6 or 7?