Yes, "Trilogy of Terror" is the right one. As I recall, the plot
centered around a doll that became animated only after one
removed a necklace or chain from around its neck. It was
the last segment of the trilogy, if memory serves, and it
must have aired in 1975 or '76. I and others who watched it
with me talk about it to this day...
Mike Wakefield
Keene State College
Keene, NH USA