See the link in post #41.
“They” is like calling all humans “they” with all the different human cultures and motivations.
Pretending there is one “they” is one reason folks are so befuddled by this stuff.
Much of the abduction discussion has the same basic cast of characters (short and tall grays, mantids on rare occasions).
As to who or what is behind the various lights, tic-tacs, triangles, etc., who knows?