wooden cupboard which rattlesbadly

[tali122]

i have a wooden cupboard which vibrates badly when you walk past it (you can hear it downstairs), but all the screws are tight , the only thing is that it doesnt stand level with the wall behind it because of a skirting board and hence can be pushed back ,upon which the front raises several centimetres from the floor.
it is worth noting that there are other cupboards not level with skirting board but they do not vibrate and rattle at all.
any info welcomed

[Ethel]

This is probably caused by a loose floorboard that runs under the cupboard and reacts when you tread on it, rather than the cupboard itself.