I heard about this yesterday, and believe it or not, couldn't find a media mention anywhere. I finally found this story doing a Google search. It wasn't easily found at any of the local TV or newspaper sites. Even the Burke campaigns email failed to mention the pollster or supply a link.
Thank you Sheboygan conservative radio WTAQ:
The Liberty Foundation and Magellan Strategies said both candidates had 47 percent support among 851 likely Wisconsin voters polled in mid-April. The conservative National Review called the results a "shocker."