OKLAHOMA CITY - You've heard of door to door sales people, but what about door to door contractors. They too, are trying to sell something, their services -- but the Better Business Bureau says watch out, especially if they say things like "I just happen to be working in your area" or "I have leftover material and will give you a good deal."

So here's what to do when a stranger shows up on your doorstep:

Ask for proof of licensing and bonding, do not pay in advance, resist high pressure sales tactics instead take their information and say you'll get back to them. Also, get a written contract, check for signage on vehicle and be wary of out of state license plates. And finally, always get three to four quotes from other contractors.

Before you hire a contractor, check them out on the Better Business Bureau website: www.bbb.org