Buck Rogers in the 25th Century (1979)

S1E14 Space Vampire

On Space Station Theta, a string of mysterious deaths has everyone baffled, except for Wilma, who knows the truth: the Vorvon, a sinister entity that creeps up on its prey and siphons their souls, is behind it all. As the only one aware of the danger, she realizes she is next on the Vorvon's list.