Dimmer switches on when lights in the next room switch off

[Mud Hut]

I have one of those dimmers in a bedroom that doesn't have a pot, you just touch it to operate it. Strange thing is that when i switch off the lights in the bathroom (which has 6 LV lamps) the bedroom light sometimes switches on.

Any clues?

 

[breezer]

its picking up the spike

 

[BrynRovers]

Try putting a capacitor accross the bathroom light swotch contacts (Maplin SC93B) that should suppress any spike.
But it may be that your bathroom light switch is worn and causing unecessary arcing. Try changing the bathroom switch first.

 

[Mud Hut]

Good advice, thanks both of you!