hi please could someone help

i have a volvo 240 wagon and the past little while if i'm in drive it looks like its half in N and if i'm in park its sometime still in reverse! which can be quite dangerous.
does anyone know what this could be?

thanks bill

 

It may be that the plastic shifter linkage washer is worn out or gone. I believe you can see this part from under the car where the linkage connect to the transmission. I had the problem with a 262 I had long ago (or maybe my 740), it's been a while. I got the part from the stealer for like $7 or was it $2.