A burglar is an unauthorized intruder who's neither a licensee or a business invitee to whom you would owe a duty of due care (to cover, adequately warn etc.) like you would to normal visitors of your shop. If the burglar was not a child, then you cannot be held liable on a Negligence theory because you do not owe the burglar such duty. Even if found to owe such a duty (i.e owe it to everyone) you will not be liable for any injuries If the danger of electrocution was obvious (that a reasonable person in like circumstances would have realized the danger) then the intruder will be deemed to have assumed the risk, cutting off your liability (if the intruder was not a child)
You will be liable, however, if the wiring was intentionally placed by you to protect your property (by deadly force)
In all cases, details about the nature, character and location of the wiring (within equipment, across room) will support claims of duty.