Ok, I don't think these are necessarily Halloween related, going by the placard held in the first of the photos. It mentions Spring, and the other costumes would suggest a Springtime theme as well or a proto Super Mario World do! This pair of photos date to the mid 1950s I believe, but any more than that I don't know. The first photo is pretty dull really, other than the Rag doll lady.
However, the second photo has a couple of wins going for it. I love the pair dancing in the middle, there's something very odd about that rag doll mask and the floppy dance. But take a second to take your eyes off that pair and let them drift to the couple on the far right of frame. Now that's a whole lot of vintage spooky win right there. Not convinced? Take a look at the detail below and tell me you don't get a shudder of the uncanny looking at those two. Yup.