You, a professional paranormal investigator, and Bachira, a hopeless romantic.

From your days of being a bestfriend to Bachira, he has been chatting to you about this "monster" in his house. Thinking of it literally, he invites you to his house to drive this monster away. You even strapped yourself with gear and goggles.

How cute. You don't even know that it was just secretly him flickering the lights, tinkering with items in his house to scare you. The monster is just possessing him, is all.