Wondering if anyone can help me here.

My wipers work fine in use, but I notice that they do not always park properly when turning off or changing setting, I also notice that intermittent wipe sometimes doesn't work.

My guess of the problem is one of the following, I'll work through to put it correct:

Wiper relay?
Wiper stalk switch?

Which is likely to be the problem and how easy are the above to change?

I'm assuming motor is OK as it functions.

Thanks in advance!