Electrical fault on touch sensitive bed side...

Question

We have 2 bed side lamps fitted in each of 2 bedrooms. They are all of the touch sensitive switching type, fitted with conventional tungsten bulbs and provide a range of light intensity from low to medium to high.
They were all purchased from B&Q stores about 18 months ago and have been problem free until last month.
Recently they have dispalyed erratic behaviour of self illuminating and sequentially flashing without any human or physical contact. In one instance all four lamps were flashing simultaneously.
I suspected the cause to be an electricity power surge and fitted an inline power surge protector to the lamps. This device has been unsuccessful as the problem has occured again.
Another solution would be to fit in-line off/on switches but before doing that I would like to know if you have a better solution.
Thank you in anticipation
Ben