At first I thought this was the Museum of Witchcraft and Magick in the UK (mentioned in this thread here)- but what a delight to see that there is another witchy museum! 
I was really curious so I looked it into a bit. It looks like the Museum of Contemporary Witchcraft is an upcoming witch museum in Olympia, Washington, USA.
Their homepage lists some of the witchy artifacts in their collection. It looks like the exhibit is currently located in a private home and visits must be scheduled in advance.
It is always wonderful to see positive witchy representation! 
Thanks so much for sharing the survey, @Susurrus. I’ve gone ahead and filled it out 