Is there a such thing as a vibration free trailer?

[LawnEnforcement25]

i just bought a NEW 6'X12' utility trailer from Bye Rite trailers. well, the day it was brought home, my wife actually went and bought it for me as a surprise. when she arrived home the lights connector was dragging the ground. they didnt leave enough slack to straighten up. she was at an angle when the guy came out and hooked it up for her so as soon as she straightened up it unplugged and drug down the road. Well i got that issue fixed. now, i am noticing one light flickers and when i move it a little it will stay on. i have wiggled it enough to stay on so far so im guessing loose ground or something on the light itself. anyways, i have only taken it out a few times and only on the highway maybe 2 times. i notice at about 65mph, there is a very strong vibration and i think its coming from the driver side wheel but i cant be sure. i also notice at around 40-45 mph i get the same vibration only not as strong. it seems to come on and off consistently around those speeds. is this normal or is there something wrong with the axle or wheel hub or tire or what?