Turn on to T-Bag (1988)

T.Bag has moved into the back of an old television set and intends to take over the airwaves with High-TV and put all the viewers under her spell. Professor 'Sparky' Sparkes and Children's TV presenter Holly-Anna Jones mean to stop her with a jamming device powered by nine crystals. But T.Bag takes hold of the crystals and hides them in various upcoming programmes. Now it is up to Holly to find them all before T.Bag starts her transmissions.