Fixture replacement between floor joists
I need to replace a 4" fluorescent fixture mounted between 2 floor joists (14.5' across, 9' deep) in a drop ceiling.
It currently is hack mounted resting on top of metal conduit and a piece of metal strap and not secured to the joists in anyway. The ceiling tiles are hanging slightly under the joists and there is clear, large plastice tile covering the fixture in the grid.The connection is also suspect, a piece of BX flex connects with a cut cord on the fixture and does not terminate inside the fixture nor a box (splice is hanging above next to fixture, no power to it when switch is off).
What would be the best method to replace this fixture, whether it is with another fluorescent fixture or otherwise. How should the fixture be secured between the joists?