FAbia VRs wipers won't turn off

Would be very grateful if anyone can shed some light on the following issue: a couple of weeks ago I started getting an intermittent problem, whereby when you turn the ignition on the front wipers come on and won't turn off. They run at normal speed, continous setting. Moving the stalk to intermittent setting has no effect, stalk to ON also has no effect, stalk to FAST runs them at fast.

AFter the usual random cobinations of ignition off/on/wipers on/off/windsceen wash on/off they seem to turn off then everything is fine.

The other day it happened again and I couldn't get them off at all, until I noticed that turning ON the rear wiper (stick away from you) stopped it - but then my rear wipers were on... Every time I turned the rear wipers OFF (stick toward you) the front wipers came on again continuously. Then after a minute or two of random stick movements it stopped and it hasn't happened again since....

The wheel and column haven't been disturbed, and I haven't noticed any other faults, but the apparent connection with the rear wiper being on/off suggests a column/stalk issue?

Just wondering whether anyone else has had this issue and can shed some light on it, before I go pulling things apart...

thanks in advance :-)