Not needed results

Elasticsearch version 2.3.3.

I have a document indexed with _id: 506GBBO25953J. And I want to get only this one document. The problem is that I also get 9 other not needed documents.

{"query": {"term": {"_id": "506GBBO25953J"}}}


grep "_id" /tmp/dump 
      "_id" : "506GBBO25953J",
      "_id" : "404DDCN87823H",
      "_id" : "182JNYT51862G",
      "_id" : "928NSDK72999J",
      "_id" : "880RFWM18773C",
      "_id" : "963WLQD56637O",
      "_id" : "042BRRR44674H",
      "_id" : "905SWQI56804W",
      "_id" : "776DUXN15235Y",
      "_id" : "723CJRP41700R",

Also I tried bool query for a field in _source, same result.

{"query": {"bool": {"filter": [{"term": {"ID": "506GBBO25953J"}}]}}}

Why is that? How to return only one document?

An ID is unique within an index and type.
Not sure what search you ran across what indices there and how you got tmp/dump but normally retrieving documents by ID is done using the full URL e.g.

GET /myindex/mytype/506GBBO25953J

This is not a search operation which is broadcast across all indices and shards. It is a targeted retrieval from exactly one shard using special routing logic. The GET operation is normally exposed by language clients as a get-by-id operation distinct from the search functions.