In fact, I'd say there are only rare occasions in which a person can be smiling or laughing and not actually be happy. For instance, we may end up feeling amused when someone flips onto their back having stepped on a banana peel...but we're not truly happy. We may smile when we find out that a backstabbing former 'friend' got fired from his job...but again, we're not truly happy. We may repeat mantras like, "what goes around, comes around," and similar types of phrases...but that is not happiness.
But outside of these types of examples, behaviours like smiling and laughing all are known not only to be a product of happiness - a side-effect of sorts - but they also induce happiness!
We smile when we are happy and we can make ourselves happy by smiling and laughing! It works both ways!
Smile and laugh as often as you can; you will find your attitude will be more light-hearted!