Just make sure you're using the right torches. 
Terraria Community Forums
Adapting
Terraria_pro99
Rainbow torchs
Travlordian01⚡️
Naa it’s hallow torches
TerrariaGeek401
I think that event is really interesting. It seems a lot like something that would be in a mod, to tell you the truth. Also, any torch works for the event, the wiki says.
TerrariaGeek401
Also, anyone else think it's a little weird that you can only do the event once? Seems like there should be a way to do it more than that one time.
Adapting
Once per day we make more sense. (in-game day)