One possible motive could be robbery. He might be planning to use the knife to threaten the occupants of the house and steal their valuables.
Maybe he is playing a prank on someone. He wants to scare his friend or family member when they enter the room.
There was a man under the bed with a knife. This man was a mentally ill patient who had escaped from a nearby asylum. He found his way into this random house and hid under the bed. The family living there started to notice strange noises. The man under the bed was just waiting for the night to fall completely so that he could come out and find some food. Fortunately, the family dog sensed something was wrong and started barking, scaring the man away.
Perhaps he was looking for something that he thought might be under the bed, like a lost toy or a book. He got so involved in the search that he just stayed there for a while.
Well, in a fictional and very dark context, it could potentially be about revenge. If a woman has been severely wronged by a man in the story, perhaps in an extreme and misogynistic way, she might be depicted as taking this drastic measure out of extreme anger and a desire to cause the ultimate harm. But this is a very disturbing and unethical concept.
One possible motive could be related to a crime plot. For example, the person tying her up might be involved in some sort of illegal activity like blackmail or ransom, and they use the hotel as a secluded place to carry out their evil plan. Another motive could be part of a psychological thriller scenario, where the person has some mental disorder and gets some sort of twisted pleasure from tying the wife up. It could also be part of a mystery story, where the situation is set up to mislead the reader or the investigators in the story.
Well, here's a story. There was a man under the bed in an old, haunted house. The people who moved in didn't know he was there. Every night, they would feel a cold draft. One day, they dropped a coin under the bed. When they reached for it, they saw the man's pale face. He was a ghost who had died in that room long ago and was trapped there, and his presence was always under the bed.
The character with the knife might have a motive of revenge. Maybe they think BTS has done something to them or someone they care about, even if it's just in their own deluded mind. For example, they could believe that BTS stole their chance at stardom. Or, they might be part of a rival group's fanbase and are acting out of extreme fan loyalty in a very wrong way, thinking that by getting rid of BTS their favorite group will have more success.
In another scenario, the boy could call for help. His dog, which was sleeping outside the room, comes running in. The dog bravely barks at the thing under the bed, scaring it away. The boy then hugs his dog tightly and decides to never sleep in that room again until he is sure it's safe.
Maybe Snape is being controlled by some dark magic or a curse that makes him act this way against his normal nature.
He might be suffering from a terminal illness and wants to end his life on his own terms rather than endure a long and painful decline. So he hires an assassin to make it happen quickly.