There's a new face on the North Penn School Board.   Towamencin Township resident Josie Charnock Tuesday night was selected by other board members to fill a seat that has been vacant since the start of the month.   She's been active on the District Safe Schools Advisory Committee.   Charnock replaces long time school board member Terry Prykowski.   She stepped down from the school board July 1st after serving on it for more than 15 years.