Eerie sightings
I believe the answer is:
ufos
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">eerie sightings</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ufos that I've seen before include "Supposed alien craft" , "Potential alien craft" , "Roswell sightings?" , "Mysterious phenomena" , "Strange aerial objects" .)