Device Enrollment notification from unknown source keeps popping up

I keep getting the notifications no matter where I login to WiFi. I've used my "Personal Hotspot" and it showed up. I logged into WiFi at an airport, it showed up. Logged into WiFi at my office, it showed up. Every single time I login to any WiFi at all, it suddenly appears.

First of all, many thanks to you for taking the time to reply to my query. I appreciate it very much.

I'm traveling overseas and just logged into the WiFi at the airport and as I was looking for a Profiles in System Preferences the same "Device Enrollment" request came up. I've taken a screen shot to post here. I have no idea why Jackson County School District no. 9 in Oregon -- a place I have not visited in many years, would be trying to enroll my MBA.

Something occurs to me ... In August 2014 I had to replace the Logic Board of my MBA (water spill). I'll bet the serial number of my Logic Board (bought via eBay because it came with an extended warranty) is linked to that school district. If that's the case, it's odd that it only started showing up after I upgraded to OS X El Capitan (and that I've seen other posts on the discussion boards about people having a similar problem after upgrading.).

Update: I contacted the school district that shows up on my Device Enrollment notice and heard back from them same day --even though it was a Sunday -- and found out that my Logic Board, the one that I bought via eBay in September 2014, was stolen from that school district.

Of course it was not a pleasant outcome knowing that I was involved in purchasing something from a "fence" operation but it explains why I've been getting these messages.