Warning letter - employee visited the consumer's premises without permission

One of our field employee visited the consumer's premises without permission, I just want to issue him a warning letter and want to advise him to be careful in future while performing his duties . Pls sent a sample format for this.

I would suggested you made a draft and posted. Does your offer letter cover that employee should not visit the consumer premises in 1st place? Please see, if counselling itself would help in 1st case, until you want to put in record and record the same in PD.
thanks

Dear Deepak,
Unable to understand the indiscipline involved in visiting a consumer's premises. Strictly speaking its a positive thing that an employee want to experience the customer / consumer's related issues. However if the point is communicated to the employee through either mode then you can initiate action but if it is the first time then better to restrict it to a warning.
Regards
Kameswararao S

Deepak,
Background of the issue needs to be made clear.
Why employee cannot visit customer premises?
Normally field employee visiting customer premises is discharge of his duty.
How do you know employee visited customer premises?Was there a complaint or some issue?
Unless you specify details answers will be incomplete.

Was there a complaint from the consumer first ? Secondly, as opined by professionals above, if there are clear SOPs ie Standard Operating Procedures against such visits, why unnecessarily create a precedence of sorts. If the visit is something for a personal gain or he is chasing or stalking a woman consumer with improper motives, then you can certainly issue a warning letter. Again, first stage is verbal / oral counselling by his Immediate superior or HOD in your presence. It is possible the employee may be new to the job role and could be a bit over-enthusiastic. So, first find the facts, and counsel him and ensure that this is not repeated. If he is a serial offender, then the matter is different. So, please provide clarity first.
Best wishes