I wonder if someone can help

I am retired and recently had to move into a Nursing Home due to ill health.

The Wi-Fi in the nursing home is, in a word, terrible and the IT dept has been less that helpfull and possibly incompetant.

I am using inSSIDer free. Could someone please provide a graph or two of what good signal levels should be from a Wi-Fi Access Point.
I am getting a reading of -58dBm DIRECTLY UNDER the closest access point and with the signal levels (graph) in my room (approx 25ft away) going up and down like a yoyo - in the range of -60dBm down to -85dBm not unlike a square wave.

I figure directly under an access point the power level should be between -30dBm and -40dBm.

(I think/hope) I have attached a couple of screenshots of example of what I get and the sort of graph I would like to recieve.

Many thanks in advance
Ian