Who called from 2404158103

Postcard stating a delivery was missed, problem is that it was sent to me via postal delivery from Baltimore instead of the typical "missed you" notice.
Company in the card says W.W.T. Inc ph# 240-415-8103

What is it trying to deliver? Or is it someone trying to serve u ? help

I received the post card and called the number since I just bought a new house.  They called back at 9pm and said they were from Watts and mentioned whole house water purifying systems.  I asked why they sent a bogus post card and they hung up.  Help?  What is this??

Got a call earlier while at work this afternoon. I don't think I got a voicmail. Does anyone know who this is?

Oh they did leave a message. It was my water treatment company offering to schedule my 25 year follow up inspection.