If you want to use dnd 5e sandy Peterson did a couple adventures and a base ruleset called Cuthulhu Mythos. Theyre a lot of fun and totally built around suspense. Page 70 starts the chapter where they review insanity and dread. I love the dread mechanic.

Not much in 5e. Maybe cr 3 for the whole thing. A party of lvl 1 could do it assuming they don’t roll bad on saving throws for the traps. The wasp and glass part seems most dangeous. If party is likely to just bum rush it, maybe cr4 and a party of level 2

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