Taylor Swift Wedding: Strict Rules For MSG Event Staff, In Dark About Ceremony

Madison Square Garden employees are being cut off from the outside world while setting things up for Taylor Swift and Travis Kelce's mega-bash this week ... because they're not allowed to have their phones while they work.

Employees who work in event production for MSG tell us ... they can't have their phones during the shift, and while they haven't been told why, it's presumably so they can't take pictures of the setup.

We're also told employees are wearing wrist bands -- which is out of the ordinary -- and they have to go through an extra layer of security when they show up to work.

Multiple employees also tell us they're working blindly ... basically, no one has told them who is behind the big event they're working on. One person we spoke to even told us he thought it was a graduation -- because there are tons of curtains inside.

We're told event staff is scheduled to be in the building early Friday morning.

Of course, we know Taylor and Travis rented out Madison Square Garden for this weekend ... spending millions of dollars to do so.

Despite that, the pair is trying to keep the rest of the details pretty quiet ... watermarking individual invitations to dissuade leaks and sending an NDA to their guests.

National Guard members are closing down the streets around MSG prior to the big day ... and locals have already told us they're not happy about how the enhanced security's going to affect the holiday weekend.