to/in which

 I keep thinking 'to which' is correct, but 'in which' sounds better to the ear...

  'The matter IN WHICH/TO WHICH you have become accustomed (to)'

Thanks

Hi Anon

If you say "I have become accustomed to something", then you would have to use 'to which' this way:
"That is something to which I have become accustomed."

You need the word 'to' and the word 'to' would not be repeated at the end of the sentence.


EDIT:
Did you really intend to use the word 'matter'?  It sounds a bit odd.  Or were you thinking of 'manner'?

"I did something in the manner to which I had become accustomed."