What happens if while spraying the alcohol sanitizer , it went in my mouth ?

No problem: The active ingredient in some hand sanitizers is methanol (methyl alcohol, wood alcohol), which is a deadly poison in large amounts. However, a minor spray in the mouth would be harmless. Most hand sanitizers contain ethanol (i.e. ethyl alcohol), the same as beer, wine, and all alcoholic beveragges. Drinking a lot of it would make you drunk, but that's all; no other harm.