Helen Connelly's (Ashley) quite life is thrown off balance by strange phone calls from a boy claiming to be her nephew who died 15 years earlier. They're more of an annoyance until the boy starts making threats and people start dying. She turns to her ex husband Doremus (Gazzara) and the boy's grown brother Greg (Douglas) for emotional support as the circumstances escalate. Will she be the next victim of the deranged ghost-child? Look for Al Waxman - the chief from Cagney and Lacey as the town sheriff.
This is one of those seen and forgotten made-for-TV movies from the 70's. They were numerous and ubiquitous. Many of them are quite good. It's available on DVD, thanks to Michael Douglas' involvement in it, and it can be seen in full on YouTube. Part one is above, uploaded by TVTERRORLAND.
Obscurity factor: 8 (not well remembered, on DVD & YouTube)