What flaps position should be used for taking off from a wet runway?
The POH for a 152 lists the flap settings for takeoff as between 0&deg; and 10&deg;. It makes no specific mention of take off from a wet runway, however you could follow the same procedures for a soft/rough runway if you are concerned about the surface conditions.


  Soft or rough field take off are performed with 10&deg; wing flaps by lifting the aircraft off the ground as soon as practical in a slightly tail low attitude. If no obstacles are ahead, the airplane should be leveled off immediately to accelerate to a higher climb speed


Source: Cessna 152 POH Section4 (Normal procedures)

I should note though that in roughly 180 hours on C150/152's and a short (650m) hard runway, I've never felt the need to even use flaps, let alone execute a soft/rough field takeoff as described above. It's not a particularly comfortable take off, and a wet hard-surface runway doesn't really present that much of a problem.