anyone know of any thay is reliable and easy to attach.is anyone fimiliar with the (bowman switch) its suppose to activate when set when you reach full draw

Some sight makers have a light that is made for their sights. That being said, the problem I find with most lights is that when you need them the most they make the pins too bright, washing out the target (deer). You can't see anything on the other side of the pin. And electrical devices being what they are, batteries do wear out, necessitating new ones at nearly $3 each. And some take 3 batteries.

I would opt for one of the decent quality wrapped fiber sights instead. No battereies needed and they automatically dim withe ambient light. I use an HHA OL-5000 and it works well. Bright enough that I can still see the pin nearly 1/2 hour after I need to leave my stand. Cobra Sidewinder is another one, and there are getting to be more.
Depending on what sight you have, if it's got fiber optics, you may be able to just get long fibers to replace what's in it now. Longer fiber gathers more light.

Just a suggestion.