A long shot, admittedly.....

I was a little kid, growing up in Lewistown, Montana.
For the time, we had a very progressive but experimental cable company. We got lots of channels and programs that few other, larger cities had (Lewistown in the early 70s had a population of 5,000 people).
I remember watching a scary TV show, but remember few details about it. What I remember has stuck with me for the following 35 years since seeing it, though. An older woman is puttering around in a garden, as I recall. She sees another woman's hand reaching out of the ground, and dropping the trowel she was holding, she tells the buried woman that she'll help her. She then grasps the other woman's hand and attempts to pull her out of the ground. That's really all I remember, but it scared me enough I couldn't sleep at all that night. My friends had also seen it and we talked about it the following day on the school playground. That's all I know! Anyone have any ideas?