2010 Renault Modus smoke from wiper motor stalk

on cleaning the screen, whilst driving , smoke billowed out from RHS Steering Column at the wiper swith stalk. Turned off wipers, stopped car....all ok EXCEPT more smoke when wipers switch operated. Took off lower shroud to steering column..TWO TORX SCREWS..removed and opened the Wiper Stalk BOX ( other switch gear for AUDIO CONTROLS /COMPUTER SCREEN BUTTONS in DASH BINNACLE also in the BOX) Melted/burnt areas at WIPER SWITCH area. Surprised that it nearly caused a fire...BUT.... no fuses blown, and the wipers still move correctly BUT switch unit SMOKES A LOT !! IF wiper motor was faulty, why hasn't a SOLENOID/RELAY or FUSE protected against excess current at the SWITCH STALK box unit?