Vocabulary 'In light of'

Not really. That sentence about the cockroach sounds very awkward. You could use the expression 'in light of' by reworking the sentence a bit. Example: In light of the fact that I had seen a cockroach in my room, I found it difficult to sleep that night. The point is that the 'in light of' doesn't really refer to the roach itself but, rather, to the situation now existing in your room. Often a sentence will begin with an expression like 'In light of the fact that ...' [etc.] Again, you're speaking of a situation or a fact, an event rather than a 'thing.'

Hi Andrei,
thanks. I have one more question, what is the difference between in light of and because of?

The difference is somewhat subtle. But 'because of' implies that whatever it is you're talking about was the cause of something. 'In light of' does not imply this at all; it is just a way of saying that something will happen (or has happened) because a situation exists. Two ways to put the same thought:
(1) In light of the fact that our budget was over-extended, we decided to curtail our vacation plans.
(2) We curtailed our vacation plans because of our over-extended budget.

I said the difference is subtle. But in the first sentence you are explaining why the vacation plans were curtailed. In the secod sentece you are saying that the budget problem was, indeed, the cause.

When in doubt, I'd use 'because' rather than 'in light of'.

Thank you very much.