If they are the older ones with Local Control Sensing. There are some modifications for them but if it is the relay on or off sensor. Defeating it causes a machine gun ratchet sound.
You may find it easier to try a 39k {39,000 OHM} 1/2 watt resistor across the output. Again you could try mounting one in a plug for a test.
39K gives you a safety margin on the 1/2 watt resistor as it dissipates .37 watts.
Can go lower if we go to a 1 watt resistor, but many find the 39K fine.
Has anyone tried this with a wall switch?
I have an X10 wall switch (WS467 I think). It's been controlling the lights on my bedroom ceiling fan for years. I'd like to switch from incandescent lamps to LED lamps in the fan.
Ikea has some GU10 base LED lamps for $10/each. I have some standard Edison (E27) base to GU10 base converters.
If I leave an incandescent lamp in one of the 4 sockets, the switch works fine. If I put LED lamps in all 4 sockets, they just blink/flash; but never come on fully or go off fully.
I have the ceiling fan disassembled at the moment to paint it, so the light kit part is easy to experiment with. If I wire a standard 2-prong plug onto the light kit, put the same Ikea LED lamps, in the same Edison to GU10 converters and plug this assembly into an X10 2-prong Lamp Module, they turn on and off from a remote keypad just fine.
I don't have a neutral wire available in the box in the wall where this switch lives, so I can't easily implement the "add a neutral to support CFL' mod; which would probably work just as well for LED lamps as CFL lamps.
Anyone have any suggestions for modifications I can try with my existing switch (I have a couple available to test with), so I can make these lamps work without having to buy a new/different X10 switch?