Why banner ad from adsense?

window.document.getElementById(‘post-3845’).parentNode.className += ‘ adhesive_post’;I’m wondering if anyone knows why google would be placing a banner ad on one of my pages. I have the same "adsense for content" code on all pages and it works fine except one page gets a banner ad for a gas grill (nothing about gas grills on my site) at Consumer Reports.
I guess I’m not experienced enough to have seen this before.

Original post by downloadthenet