They can get in just about anything alarm clocks, behind pictures on the wall or bedside tables, and of course bedding, furniture anything stuffed. and stuffed animals.. 

Raise them because they might have stuffed any tenant in there to make it look good for potential buyers without taking into account tenant quality.  

The cost is C H E A P like $125/yr and as it's their property, setting a minimum coverage is foolish IMO.2014, my upstairs tenant started a fire in a stuffed chair causing $95k damages to the property and about 75% loss of their personal property. 

If much of the basic basement finishing happened way back when, you probably have, behind the walls, plastic sheeting stretched across the concrete block walls, fiberglass batts stuffed into the rim joist cavities, organic fiberboard insulation lining the plastic, and regular drywall with untreated 2x2's serving as studs, nailed into the concrete masonry block walls with a powder-actuated nailer.

Most people would say that instead of stuffing envelopes you can be out looking for deals but I understand where you're coming from regarding having a tight budget.

The tenants absolutely LOVE getting them and it helps me as I would have ended up buying those boxes anyway so my daughters can get the stuffed animal or another prize.

The crowd dragged my friend and his luggage out of his car, stuffed the German in, and sent him and my friends driver to the hospital.

Thanks @Roy_N. and @Erik_Noordam (mentions still not working, stuffing it in for posteriority)Erik, I will of course consult the usual suspects, but I'm trying to get my head around it myself first.

Takes one tenant stuffing something strange down the line to cause a problem.  

I printed all letters, folded, stuffed in envelope and put a stamp.