It would be interesting to know if the Airport Authority know they've been put there.
That may sound almost unbeliveable, but over the years I've seen many similar things installed on airfields by the maintenance personnel which go against every rule in the book, often they're not discovered, especially if they're in a remote field location outwith the airport itself, until someone from another department sees them or the CAA Aerodrome Inspector pays a visit.
These lights are, as with many airfields, clearly in a field which would only normally be visited by those who maintain it and the farmer.
Perhaps those who run Alderney should be told?