One possible plot could be that a person wakes up in the morning thinking it's a day of good luck. But as the day progresses, they start to notice strange things. Every so - called 'lucky' event is actually a setup for something more sinister. For example, they win a free trip to an old, abandoned hotel. Once there, they realize that the 'good luck' was a curse to draw them into this horror - filled place where they are haunted by the ghosts of the hotel's past victims.
A plot might be that a girl is told she'll have good luck all day. She finds money on the street and gets a promotion at work. But then, she starts seeing a shadowy figure everywhere she goes. It turns out that the 'good luck' was a bribe from a malevolent spirit. The spirit wants her soul in exchange for the good fortune and starts to torment her, slowly taking away all the good things that happened that day, leaving her in a state of horror.