Original excerpt:
It is important to ensure that the document witch contains sensitive information is properly stored.
A document in multiple folders are supposed to have sensitive information redacted when possible.
Because, of the sensitivity of the information, workers should be more careful in which documents they share with team members outside of the building.
Corrected excerpt:
1) It is important to ensure that the document, which contains sensitive information, is properly stored.
(Add comma after document)
(Change witch to which)
(Add comma after information)
2) A document in multiple folders is supposed to have sensitive information redacted when possible.
(Change are to is)
3) Because of the sensitivity of the information, workers should be more careful about which documents they share with team members outside of the building.
(Remove comma after Because)
(Change in to about)