Trying to install new track lighting into old box
We are trying to install a new track lighting fixture into an old, too small rectangular ceiling box. There was old track lighting there that we estimate was installed in the early 1970s (if not before, if that was possible). We are replacing it because replacement lights can no longer be purchased and it was very very dirty. The house was built in 1958.
First we noticed that the box is crammed full of wires, the wires are very stiff and there are two white and two black wires. There is not room to stuff the newly connected new wire and the two old wires. I think we should shorten the old wires by at least an inch or two. Is this OK?
Second, the box is small and rectangular--the size of a switch or outlet, with a metal bracket that was from the old track lighting. we removed the bracket and then realized that there was no place to attach the new bracket. We reattached the old bracket and we were going to attach the new bracket to the old one, but realized we would be screwing into plaster--not the box. Is this OK? the fixture does not weigh very much and the track will be supported by several screws.
Where should we ground it? the only ground screw was on the old fixture.
All suggestions are welcome.