rewiring a vornado air circulator fan

Hello - although many posts have dealt with installing a new light fixture and then being unable to turn it off, I haven't seen my exact situation yet. I have 2 white wires, 2 black wires and 2 grounds coming from the wall in two different places in the metal electrical box. Also, inside the box is a small, plastic square-shaped box (approximately 1 x 1 1/2 inches) with four small holes in it, into which are attached the 2 black wall wires and the black light fixture wire - one hole was left empty. This box has writing on it which says "Heavy duty t-load charge 1/2 hp 125 vac). When I removed the old fixture, the 2 white wires and the white fixture wire (3 in total) were twisted together and capped, which I've repeated. The 2 grounds were grounded to a screw on the electrical box, and there was no previous ground, so I've now grounded the new fixture's ground wire to the plate screw. I did not move either of the two black wires that came from the wall - they are still plugged into the same holes in this plastic box), and I plugged the new fixture's black wire into the same hole as the old fixture's. However, when I flip the breaker, the light fixture comes on, but can't be turned off using either of the 2 switches that previously could control this light. I didn't touch the switches at all. A 2nd light that is controlled by the same 2 switches does turn on and off successfully. The only other information that might be pertinent is that this house was built in the 1970's using low-voltage switches throughout. I'm wondering if this plastic box has something to do with these switches, and if anyone might be able to advise me how to fix this fixture! Thanks in advance.

I purchased three Hunter ceiling fans. I had an electrician install all three. One of them has a ticking noise when running the fan on the highest speed. I purchased the Hunter fans because of the good name. What might be causing this ticking? Neither of the other two fans tick at high speed. Thank you