Wood knob hose. Cut two small washers from a sheet of medium-grade emery cloth. Paste back to back. Insert between the knob and the drawer.
If knob
is loose because the screw hole in the back of it has enlarged, fill hole with plastic wood and reset screw at once.
Threads on bolt of metal knob gone; nut pulls off. Try a smaller nut. If this doesn't work, rub plastic steel into threads, tighten old nut, and coat joint between nut and bolt with more plastic.