I get a sewer smell in my house when I am away for a few days. No smell when I am home. I think the problem is one of my toilets when I get the smell there is no water in the bowl. Yesterday I flushed the toilet checked the to see where the water line in the bowl was and two hours later I checked and the water line was down about half way. Could I have have a bad toilet or wax seal. Any help would help

Obviously the smell and the disappearing water in the toilet are linked.
How can water disappear that fast in a toilet? Not by evaporation.
So either there is a leak in the toilet bowl itself, or there is something allowing the water to pass through the waterlock in the bottom of the bowl. It can be that something like toilet paper got stuck in the bottom section, allowing water to drip out. Flush a couple of times after each other and see if the problem stops.
If not : unscrew the toilet from the ground (or wall) mounting, and inspect the bowl and the rubber seal as to what is causing the problem.

Success !

:)

There could also be a factory defect in the bowl. Sometimes in casting the bowl there is a small bubble in the china. Instead of junking the bowl the manufacture will put a porcelain patch over the hole and send it on through. On occasion the patch will fail allowing the water to seep out of the bowl. If that's the case you would have a full bowl after you flushed and the bowl filled but some time later you would notice a drop in the bowl level. The only other thing might be if you dropped something in the bowl and cracked it. If you're worried about where the water's going, in both cases it drains back down into the sewer and not under the bowl on the floor. To check the bowl must be pulled, filled and put up on saw horses. You can then see if there's any leakage from the bowl.
Sometimes a blocked vent can "vacuum" water out of a bowl. Does the level "bounce" up and down? Regards, Tom