Searching for mid 80s light horror where kid has a treehouse

So I once saw this film which I remember very little of. I think it was supposed to be horror, but the horror element might have been very minor.. as it might very well have been just a scary kids movie.

I think I saw it in 1987 or 1988.

As far as I can remember, the setup was the standard "family moves into house that turns out to be haunted".

And there might have been some monster character with multicolored bubbles in his skin.. Kinda like the Polkadot man from James Gunn's Suicide Squad... only meant to be scary.

All the stuff above is hazy though, and I might be mixing movies here.

But what I do remember, is that a kid had a nice treehouse, which he could climb into from a window. It wasn't a big part of the plot or anything... but I guess that treehouse must have made an impression, because it's basically the only thing I can see clearly in my mind.

I thought for a while that the film might be Mr. Boogedy, but it turns out... no treehouse in that.

EDIT: I remember there was a scene where the parents discovered that the kid was not sleeping in his bed, so they checked the treehouse and found him sleeping there.