The following is an example of a visit letter.
Dear xxx,
When I called at my office this morning, I was very sorry to learn that you were sick. I am writing this letter to extend my best wishes for your quick recovery. Please accept the attached greeting card I sent to you. I do hope you enjoy.
If I can be of assistance to you, I hope you will let me know at once. I hope that by the time this letter reaches you, you’ll be feeling much better. I am looking forward to chatting with my old friend on line again.
Yours truly,
Xxx