[Any][1], adjective:


 >- You use any in front of a singular countable noun to talk about each thing or person of a particular type. *Look it up in any large dictionary.
These are things that any man might do under pressure.*


>- You use any in front of a plural countable noun to talk about all things or people of a particular type.
*The patients know their rights like any other consumers.
You use any in front of an uncountable noun to talk about an amount of something.
Throw any leftovers in the bin.*

>- When you use any in front of a singular countable noun or an uncountable noun, you use a singular form of a verb with it.
*Any book that attracts children as much as this has to be taken seriously.
While any poverty remains, it must have the first priority.*

>- When you use any in front of a plural countable noun, you use a plural form of a verb with it.
 *Before any decisions are made, ministers are carrying out a full enquiry.*


[Ngram][2] shows a more common use of the singular form in this case. 


  [1]: http://www.thefreedictionary.com/Any
  [2]: https://books.google.com/ngrams/graph?content=In%20any%20situation,In%20any%20situations,%20in%20any%20situation,%20in%20any%20situations&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1;,In%20any%20situation;,c0;.t1;,In%20any%20situations;,c0;.t1;,in%20any%20situation;,c0;.t1;,in%20any%20situations;,c0