My Light 15 (53) does the same. The oil light flickers on tick over and has done since I purchased it some 18 years ago. Oil is changed regularly – used Castrol classic and Millers over the years but light still flicker. Too awkward to get to the oil switch!
Now I worry about the alternator light flickering at low revs – just a poor light contact that needs to be wiggled – but… hey ho!
Alistair
Alistair