I have interference from an out of bounds fence, stake or wall -  what are my options? 

You do not get free relief from objects that define or mark the course boundary. You may not move objects marking course boundaries or take free relief from them like you would from other artificial objects, like a cart path, a building, or a stake marking a penalty area. Your options are to play your ball as it lies, proceed under penalty of stroke and distance by playing again from the spot of your last stroke (see Rule 18.1), or decide your ball is unplayable (see Rule 19.1).