I have a neibhor that leaves boards outside my door with nails sticking up, probably hoping I will step on the?

Unless you front porch is facing the work he is doing, both OSHA and the Police can do nothing as you have no proof it was even him putting the boards there. Best would to politely ask if it is him and if he has an issue with you or any one living with you, and resolve the issue. If he denies it, put a hiden video camera up and catch him doing it, then you can call the Police!