When tuberculosis started raging through New England in the mid-1800s, people watched as patients slowly withered away from the disease, carefully considered every possible explanation, and decided it was vampires draining their life force.
So far, so 19th century. These were no ordinary Draculas, though: It was believed to be caused by a family member who had succumbed to the disease rising from the grave to feed on their loved ones (it tended to spread between family members for some reason).
To counteract the curse, people dug up the graves of suspected vampires and inspected them for signs of undeadness, such as fresh blood in the heart, which could have been caused by a number of things that don't include vampirism. What happened next depended on how flashy they felt like getting with it. Some vampire hunters simply turned the corpse facedown, because apparently, vampires can rock, but cannot roll, while others held ritual burnings of the offending organ on the town square so everyone could inhale that sweet tuberculosis-curing heart smoke. (Spoiler: It didn't work.) In one particularly famous case, the ashes of the heart of a young woman named Mercy Brown were fed to her brother with the hope of curing his tuberculosis. It's unclear why, after several other women in the family had fallen to the disease, none of them were offered a bowl of death pudding.
What makes all this incredibly weird is that it was going on long after germ theory was understood and widely accepted. In fact, when Mercy Brown's 1892 exhumation was reported by a Pennsylvania newspaper, it was described as the result of a "horrible superstition," so it's not like everyone was going around throwing garlic at anyone who cleared their throat in public. It was like if there was a whole movement today that refused to accept how a highly contagious disease was spread from person to person and thought drinking bleach would-- oh, shit.
Top image: Wiki Commons