When the DJ announced a contest, the phones 'lit up'. [=the lights on the phones lit up because many people were calling]
His eyes/face 'lit up' [=he looked very happy and pleased] when she walked in the room.
He 'lit into' his employees for their sloppy work. [=he criticized them very harshly]
(..) What is it? Just before you went into the hospital, there was this... I felt an ache in my hip. So, I had a PET scan... and it lit up like a Christmas tree. The lining of my chest and my liver... Everywhere. I'm sorry. (..)2014 The Fault in Our Stars
(..) Ah, a fatal... Hazel Grace, they don't actually hurt you unless you light them. Hmm? I've never lit one. It's a metaphor, see? You put the thing that does the killing right between your teeth... but you never give it the power to kill you. (..)2014 The Fault in Our Stars