I haven't seen this unusual invitation before. I meant to place a bid for it but got distracted with other things. The seller, a wonderful person, states that it is from 1938, and it may very well be. The art seems to be transitional, toggling between the extremes of solemnity and fun. (Look at the listless lantern, the scared cat and the harmless JOL behind the blindfolded boy.) I feel it is more likely from the late 1940s. Who knows? What I do know is that whomever bought it swept it up for a good price.
Mark B. Ledenbach's vintage Halloween collectibles blog.