While doing the “te iru aida ni (while…)” grammar point, I came across this example:
休を取っている間あいだに ボスに_話かけられた_。
which is translated as:
While I was on break, my boss talked to me (to my dismay).
That 話かけられた is what I don’t understand.
I think it’s in passive form, seeing “boss ni” and “-rareta”.
But, then, what about that “kake” in the middle of the verb?
Thank you for clarification.
Hey! 
話かける is the second way (and less common) of writing 話しかける - to address someone/ to speak to someone.
So like you said, 話かけられた is passive of 話かける（話しかける）and means to be addressed by someone.
I hope it is clear now 
Edit: Changed it. 
Oh, so it’s another verb!
And here I thought it was another particle or conjugational suffix added to “hanasu” (to speak).
Thank you so much for your response.
: )
Not a problem