For an indie filmmaker, there can be a lot of advantages to filming in your own home: No need for permits, no time restrictions, and you can manipulate the surroundings any way you wish. When Ian Tuason was preparing his directorial debut, “ Undertone ,” it was a no-brainer choice for the low-budget film. Yet shooting a horror movie in his home had an unintended effect. “The house got haunted, and I had to live in it,” he says. “I was the one who had to sleep in it. I got desensitized, but wasn’