2001 Dodge Durango flickering dash and tail lights

when our lights are on the dash lights and tail lights flicker...there's a tickling/flicking type sound along with this...our mechanic replaced the on/off light switch...that wasn't it...he's going thru the wires as I write...there's another part $230 or so that he said rarely goes out according to his Dodge source...he's stumped...Is this an odd ball thing? Will we be bankrupt before a solution is found? Help please! Thanks...PamB