The wanderer is a scavenger. He will go and scavenge the items that you requested.
How he works:
You find them in the world and escape with them. If you escaped with him, he will show up in your base camp. Once he is in your base camp you can talk to him. You will be provided three options, one gun and two weapon mods. You can spend blueprints or exchange weapons to increases the rarity of the Items. At the end of the week he will leave your camp to go get the items restarting the search for him.

Where's the wanderer? Well someone will say one map, and someone will say another map. Because people are reporting multiple different locations in a single week, we can make a central location to report spotting’s each week.

Reply in the comments section using the template below.

Week Of:
Map:
Non-Detailed Location:
Detailed Location:
Photo (optional):
Video (optional):

Example:

Week Of: November 19th, 2018
Map: Hell or high water
Non-Detailed Location: End of map
Detailed Location: They are on the right side next to the alternative escape in the garage were a survivor can some times spawn. The garage is next to a sand box.
Photo (optional):
Video (optional):

Section added because there is some confusion about things.

Q: What map dose he show up on?
A: He shows up on a different map each week.

Q: How long dose he stay on the map?
A: He stays on the map all week long and dose not rotate to a new map until next week.
Example: If he is found on Last Stop on Monday he is going to be on the map Last Stop Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday until reset.

Q: When dose he reset?
A: Sundays,7PM EASTERN time for me, can't varify for other time zones.

Q: I can’t find him, what now?
A: Look to the comments to see if anyone reported a location if you can't find him on your own.

Q: I looked at the comments and still can't find him, what now?
A: 1) He can be in two or three locations on the same map, so look around.
2) Look at more than one comment, some have photos.
3) Check the date of the comment to insure it is not last weeks location.

Q: I found him! What now?
A: escape with him.

Q: What happens if I escape with him?
A: He shows up at your camp.

Q: what dose he give you?
A: One weapon and two weapon mods of common quality.

Q: Any way to increase the quality of the items?
A: yes, you can give him weapons or blueprints to increase the quality of the items.

Q: When do I receive my items?
A: When he leaves camp for the weekly reset, the items will be placed in your vault.

Q: He left camp, but I did not receive my items, where are they?
A: If your vault if full then the items are in Caleb The Garage Manager. If your vault is not full and the items are not in Caleb The Garage Manager, then complete a map or two to see if your inventory updates.

Q: Where is Caleb The Garage Manager?
A: In your camp.

Things I have seen, but needs to be 100% confirmed.

1. The wanderer looks like he can be found on last weeks map for a short amount of time. About one hour or less befor he changes maps. The issue is you may need to be in a map during reset to work.
Example: reset happens at 7PM, you were in a map during reset and you compleated it some time after reset. You go right to the map were the wander was last week and he should be there, unless you fail. This is not 100% guaranteed to happen.

2. At reset it may take one hour befor he shows up on the new map.

3. After one hour after reset he should not be on last weeks map any more.

Maps he has show up on
Listening In
Last Stop
Open Season
Doctor's Orders
Join or Die
Hell or High Water

Maps he has not shown up on and could have him
No Sanctuary

Maps he has not shown up on and most likely not to have him (A.K.A base defences)
The First Shot
Worse Than Walkers
Home Sweet Home
At The Gates

Maps he has appeared in order so far
Listening In
Last Stop
Open Season
Doctor's Orders
Join or Die
Hell and High Water
Hell and High Water (2nd week in a row)
Doctor's Orders 12/24/18

Other thoughts
Will the wanderer stay on the original season 1 maps due to people may not buy/ own season 2 and 3 or will he show up on the new maps as well, but also the season 1 maps for non-season 2 and 3 owners.

******* The Wanderer has rotated through all the season 1 non-base defense maps over the next few weeks we will need to verify if he will rotate in the same map order or not ****

***If you have an image of the wanderer and would like it added comment like below: ***
Please add my image to guide
Map: put map name here
Image link:

NOTE: some photos will not have him in it, but were past reported spots. If you know a image is incorrect say so


HELL OR HIGH WATER
This one is above the previous photo's location

LISTENING IN
Locked room in 3rd floor
Above a Family member that can easily have a Takedown done on, there's a ladder to his right
When you reach the outpost from the ladder, look to your left, go through, and go to the left again, through the sheet metal door. Keep going and stay on the right, you'll see him inside a shack.
Looking at the door of the first image, go behind you, and go to the left, you will find these cabinets and he can be there.

OPEN SEASON

LAST STOP
From the exit elevator entrance, look behind you and go straight on the same floor

DOCTOR'S ORDERS

JOIN OR DIE