The object may come after the following phrasal verbs or it may separate the two parts:
I turned off the light.
I turned the light off.

Turn on the CD player so we can dance.

Note:            http://www.ccas.ru/olenev/english/phverbs.html
When the object of the following phrasal verb is a pronoun (it / them / me / you / him / her / us), the two parts of the phrasal verb must be separated:
I turned it off.

NOTE 2)
http://www.usingenglish.com/glossary/phrasal-verb.html
With some separable verbs, the object can before or after the particle, though when a pronoun is used it comes before the particle:

With some separable verbs, the object can before or after the particle, though when a pronoun is used it comes before the particle:
Turn the TV off.
Turn off the TV.
Turn it off.

Commom phrasal verbs
Separable
http://grammar.ccc.commnet.edu/grammar/phrasals.htm

Turn on the lights or turn the lights on?   Both ways.
Turn off the lights or turn the lights off?  Ditto here.
Turn in the report or turn the report in? Turn in the report would be more natural, at least.

Turn them off or turn off them?   Turn off them  (   With some separable verbs, when a pronoun is used it comes before the particle:                     )

Turn in it.  -  I am not a hundred percent certain, grammatically, but I would rather state the "IT" (turn the report in...);  by the above rule it would be turn it in...(have an awkward ring to my ears, I never heard or read something like this!)

  Hope it helps!