When there is no agreement as to a specific price, the law will presume that the parties intended for the price to be reasonable. In your situation, if you agreed to $55 per hour, then the time for the task would be presumed to be reasonable. If the contractor took unreasonably long or negligently increased the amount of time that it took, the contractor would not be entitled to the excessive charge.
You really need to negotiate a resolution. If you cannot, then consult with another electrician to have that electrician provide you with an estimate as to the appropriate amount of time and materials charge for the work. You can then use that proposal to negotiate with the first contractor.
Mr. Erikson is correct. It sounds like you agreed to $55 per hour. Are you saying that he is lying that it took him 100 hours or that it is an unreasonable amount of time.
Is this work being done through your insurance company? If so,. they may be able to help.
As attorney may well help you and at least make sure that if you reach an agreement that you obtain a valid release and make sure there is no lien against your property.