I’m looking for a vintage, illustrated children’s book that I believe was made in the 1940s or 1950s. In the story, a little boy (just one boy–no siblings or friends) somehow is invited to a fairy wedding and he dances and parties the whole night with the fairies, elves, goblins and toads before he has to go back home. Other details that stand out: he slides down a tunnel to get to an underground area where the “fairyland” is (my mom remembers this tunnel as starting at the base of a tree); he fills a jar with fireflies to make a lamp when walking through a dark place; at some point, either an elf or a toad or a fairy (some magical creature) is caught in something and he helps him escape and is rewarded by being a guest to a party/wedding (I think maybe the caught creature was the groom?); there is a cute little blushing bride who I believe is a fairy or something–I think the party was her wedding, but I’m not sure. My mother also remembers there being a lot of red-capped mushrooms throughout the book. Thanks!