The NZXT H1 case has come under very close scrutiny from the team at Gamers Nexus in two recent videos. It appears a fault with the PCIe riser involving conductive metal screws, an unplated PCB through hole, and an exposed 12 V plane has caused some units to catch on fire. NZXT has issued a workaround with nylon screws, but this still leaves faulty boards in place.
https://www.notebookcheck.net/Sparks-fly-as-NZXT-H1-PCIe-riser-cable-screw-fire-hazard-and-insufficient-workaround-solution-are-exposed.517787.0.html