Christmas got considerably safer around the 1910s. Before that, clipping small candles to live Christmas trees was commonplace. If that sounds like a recipe for disaster, it was. The most responsible of revelers kept their tree in the middle of the room away from anything flammable, never lit the tree if the needles felt dry, and never left it unattended.
Not everyone did that, however, and house fires weren’t uncommon. Once electricity became more widely available, electric tree lights caught on like, well, the opposite of wildfire. For the first time, trees could be left lit for hours, not minutes, and it wasn’t necessary to keep large buckets of water nearby in case the evergreen went up in flames.