Quoted on a job, 2 wall lights & change light switch from 1g into 2g to accommodate, checked wall with detector gave a tap as you do all good just plasterboard stud wall(gave that hollow sound) drop off old switch cable nice and free quick check in loft, all good, cu all circuits RCD protected its a go. Got there today started with a happy face thinking a nice little job then it's a straw wall, all the partition walls are straw aaaaaarrrrrrrrrrhhhhhhhhhh