There could be a number of explanations to the question.
When the mind is relaxed and open spirit communicate better with us.The old man could be a relative who as passed over but you don't remember him ie: great grandfather, uncle or such. Could also be one of your guides. Yes spirit will show themselves to you in the minds eye. Could be that you were been given conformation that the situation with the young lad is been taken care of. Spirit know our situations our loved ones although no longer on the physical plane will assist from the spirit realm.
When I connect/link to spirit I often get shown images of the person in my minds eye, feel their aliments or how they passed, personality etc. Try not to feel alarmed or scared by this ,if it happens again try communicating with the old man. I'm sure he would like to chat with you. Always remember you are in control not the other way round. If you do not wish to communicate with him thank him for his presence and ask him to leave with respect.(unless you feel it's something negative then command them firmly to leave without fear)