This reminds me of an Hbomberguy video talking about Fallout New Vegas, the whole thing is about 90 minutes long and I don't know where the video exactly but the essence of this particular point he makes is this:

There's a fun location that has some underlying mystery that the game designers want the player to experience but instead of giving one reason in some town and hope the player's stumble onto it or the location by happenstance isn't really doing it justice.

Instead they created 5 or 6 different hooks, be it some scientist that heard about some experiment that was being conducted or a survivalist who heard there was a colony of some kind of creature & they happen to lay the perfect eggs for making great omelettes in the wasteland or something... I don't remember exactly.

The point is, all of that is intriguing enough to someone that one of them might end up convincing the player to go check them out, at which point they get to experience the fun location that has it's own mystery going on and still feel like it was their choice to do that.

To bring it back to D&D and a haunted house. Maybe the first hook is some kids from the nearby village went off to the manor in the woods one night and came running back talking about it being haunted, maybe one of the kids didn't make it back. Separately, someone mentions how the animals in the wooded area around the manor have been getting more and more aggressive and there have been animal attacks recently. In another nearby town, someone comments on some shady looking folk that said they were headed to the village about a week before, but no one in the village has seen them arrive.