The problem is almost certainly due to natural reactance in the capacitor. The effect of the resistor is negligible but at 60Hz the capacitor has a reactance of ~26K and at 50Hz it is ~31K, probably low enough that enough current can flow into your load to operate it.
Consider placing the R and C across the input and load side rather than across the switch. The Varistor is probably not causing the problem but assuming any spikes are produced by the load, you could place it across the load or even use one on each side of the switch if you suspect mains borne transients.
Brian.