Around the turn of the 20th century, Halloween was steadily gaining popularity in the US. Picture postcards were at the height of their popularity, and Halloween gave people another excuse to send one. In the estimated 3,000 Halloween designs, we see familiar icons like witches, black cats, and pumpkins, but we also get a glimpse into some mostly bygone traditions, like petty vandalism, bobbing for apples, and trying to divine one's future spouse.
Despite its appearance, I don't think they meant to show a cat being strangled. He's just drawn that way. These vintage Halloween postcards depict children being frightened in a comical way, but the very weirdness of the images can make any modern person feel a bit ...uncomfortable. So many of them feature grim grinning pumpkinheads with uncanny and unnatural pupils that seem to be leering.
See a gallery of 60 Halloween postcards dated between 1900 and 1920 at The Public Domain Review. And since they are in the public domain, they can be shared with anyone. -via Metafilter