UFO: Target Earth (1974)

Alan Grimes, an electronic communication specialist for Gainsville University, becomes intrigued by accounts of UFOs near the Buford Power Plant after accidentally intercepting a military call to scramble some jets. He questions an astronomy professor colleague about UFOs and life on other planets before enlisting the aid of Vivian, a young woman who seems able to sense other beings she describes as pure energy. Alan and Vivian visit eye witnesses, military officials and power plant employees. Alan then uses computer analysis the data. The print-out pinpoints the lake near the power plant as the epicenter of all the phenomena. This concurs with the locals talking about lights plunging into the lake at times, especially during power outages. Once his gets his electronic equipment set up with the assistance of two faculty colleagues, he detects signals arising from the lake. They are from aliens whose spacecraft crashed into the lake a thousand years ago. They need the creative mind energy of just one more human before they can depart for home.