If I rub a polythene piece with a wool , is there a transfer of mass from wool to polythene?​

Yes, As a result, wool is positively charged while polythene is negatively charged. As a result, 1.87 1012 electrons have been transported from wool to polythene. As a result, only a sliver of mass is transferred from wool to polythene.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.