Barbara Eden in Harper Valley P.T.A. (1978)

Stella Johnson is a single mother living in the town of Harper Valley. Now most of the townspeople, particularly on the PTA board, they feel she dresses too sexy and is a little too “loose” for them, so they are making things tough for her and her daughter. When the PTA board threaten to have her daughter expelled unless Stella changes her ways, she decides to get back at them by first exposing all their hidden secrets and hypocrisy. Then pulling all sorts of humiliating pranks on them. When she decides to run for the position of PTA President, they are really infuriated and try to stop her any way they can.