It was in the 70s or 80s, I recall it was a pretty scary movie. I think people were coming back from the dead & stuff. Might have been on an island. There was a group of teen or early-twenties kids who were the 'victims'. All I remember clearly was the ending -- their Uncle (maybe father?) tells the 'kids' that it was all a test and that he wanted to make sure they were prepared to take over the company business or their inheritance or something. Also I saw it on TV although it could have been a movie just being shown on TV. I will be forever in your debt if you cab help me out. Thanks!

Not sure if on an Island, "Night of the Living Dead" was around that time.